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Additive manufacturing (AM) is a state of the art technology enabling fabrication of complex geometries, in addition to providing other advantages as compared to the traditional subtractive manufacturing methods. However, a wide variety of factors significantly influence fatigue behavior and structural performance of components made of AM metals. In addition to the fabrication process parameters, these include the effects of build direction, surface roughness, residual stresses, and heat treatment, and multiaxial stress states. At the microstructural level, defects such as pores and lack of fusion particles, as well as other microstructural features affect the behavior. In this paper, first a brief review of the aforementioned factors affecting the fatigue behavior will be presented. Then some experimental multiaxial fatigue data for selective laser melting (SLM), which is a powder bed fusion (PBF) metal AM process, of a common Ti alloy (Ti-6Al-4V) with applications in many industries are presented and discussed. The effects of surface finish, heat treatment, and stress state will be evaluated, as well as failure mechanisms in different life regimes and the role of defects. Finally, some additional factors that must be considered before wide acceptance of the AM technology in critical load bearing applications will be addressed. [ABSTRACT FROM AUTHOR]

A damage-based design procedure has been developed by the authors to predict the damage evolution and the stiffness degradation in polymeric composite laminates under fatigue loading. For a safe and reliable design against fatigue degradation and failure, the initiation of the main damage mechanisms (off-axis cracks, delamination and fiber failure) as well as their evolution are considered and suitable models are proposed for the quantitative assessment of the lifetime associated to each mechanism. In parallel, the stiffness degradation deriving from the damage evolution over the fatigue life is properly described. After the illustration of the overall damage-based strategy, the paper discusses in details the analysis and modelling of the off-axis crack initiation and propagation. The initiation of cracks in the off axis plies has been proved to be the consequence of a damage process occurring at the microscopic scale since the early stages of fatigue. On this basis, crack initiation prediction is based on the use of local stress parameters: Local Hydrostatic Stress, LHS, and Local Maximum Principal Stress, LMPS, depending on the local degree of multiaxiality of the stress state and accounting for the statistical distribution of the local laminate strength. The propagation phase is then quantified by using a conventional fracture mechanics approach. The model has been implemented in a Matlab procedure for the quantitative evaluation of the crack density in each ply of a laminate during its entire fatigue life. The knowledge of the crack density trend allows the description of the laminate stiffness evolution taking advantage of another model recently developed by the authors, valid for a generic laminate configuration and accounting for the interaction between cracks in the neighbouring plies. [ABSTRACT FROM AUTHOR]

We focus on applications from the automotive industry, on mechanical components submitted to vibration loads. On one hand, the characterization of loading for dimensioning new structures in fatigue is enriched and updated by customers data analysis. In a second hand, the loads characterization also aims to provide robust specifications dedicated to the simulation or test rigs. We aim to provide vibration specifications that are adapted to a calculation time or physical test durations in accordance with the pace imposed by the projects timeframe. The vibration specifications need to be robust by taking care of the diversity of vehicles and markets considered in the projects. In the trucks industry, the dynamic behavior can vary significantly from one configuration to another. For non-stiff structures, the lifetime depends, among other things, on the frequency content of the loads, as well as the interactions between the components of the multi-input loads. In this context, this paper proposes to compare sets of multi-input loads applied on the non-stiff structure, i.e for which the frequency content of loads impacts the damage. [ABSTRACT FROM AUTHOR]

High cycle fatigue behaviour of materials and structures is widely assessed with respect to constant amplitude loading, because of extreme simplification of experimental procedures and numerical computations. Nevertheless, fatigue strength is usually supposed to guarantee in-service integrity face to variable amplitude loading. As the fatigue response may be very sensitive to the load time history, the gap between the former two points of view results in a long-lasting debate among the fatigue community, implying the use of a damage model and the choice of a framework. The pioneering Wöhler model is the natural reference when dealing with constant amplitude loading, whereas standard load spectra are widely applied since the seminal work of Gassner. This paper takes advantage from fruitful discussions between German & French automotive researchers. It presents an appreciation of the Gassner model, usually applied by German engineers since at least 50 years, with the point of view of French engineers, more used to the Wöhler model. Neglecting any sequence effect of the load time history, thus accepting the Palmgren-Miner’s rule as an assumption, we focus on the dual representation of high cycle fatigue behaviour expressed by Wöhler & Gassner, respectively. This necessary calls for the use of load spectra (in terms of amplitude, not frequency), which are here discussed with particular attention to the automotive field. [ABSTRACT FROM AUTHOR]

Fatigue design of structural components under multiaxial loading often relies on fatigue life calculations based on a post-processing of the full-field elastic stress/strain maps obtained from finite element (FE) analysis. In the present article, a post-processing tool is adopted to compute the fatigue life of a structural component, and multiaxial fatigue assessment is carried out by considering different criteria such as that of Smith-Watson-Topper and of Fatemi-Socie. The present paper focuses on a specific structural component related to a quarter-turn heavy-duty valve actuator, called scotch yoke, commonly used in many application sectors such as oil & gas, power and chemical industries. The fatigue assessment of the component is carried out by employing a full-model FE analysis, considering fillet-welded joints exposed to in-phase constant amplitude cyclic bending-torsion fatigue load with load ratio R=-1, with applied maximum load according to EN 15714-3, which is the standard in the valve actuator sector. The elastic stress/strain field extracted from the FE model is used to perform the fatigue assessment of the fillet-welded joints, where the potential fatigue crack initiation points (weld toe and weld root) are described by adopting an effective radius at the weld notches. [ABSTRACT FROM AUTHOR]

The present paper aims to propose a method, in ISO Standard environment, in order to calculate a single global dynamic factor K AV , replacing both K A and K V , in case of gears subjected to variable velocity and loading conditions. This procedure, based on the Miner damage rule, allows to process a given load spectrum and to calculate a value of the equivalent tangential force that includes all dynamic effects; this force value is useful for bending and pitting calculation of the service life. In this work a practical case for bending strength is presented, based on a recorded flight mission, referring to a gear box for aerospace applications. Obtained results in terms of equivalent forces and global dynamic factor values have been compared to those calculated by means of the classical ISO Standard formulae, based on the corresponding experimental data. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to present three indicators to determine the fatigue limit of woven carbon-fiber epoxy-matrix laminates using the Self-Heating test method. The approach adopted in the self-heating methodology consists usually in plotting the heat transfer indicator values versus the maximum stress values. This plot is named the self-heating curve and from the profile of the self-heating curve, one can identify the fatigue limit. During the self-heating experiments, the temperature of the specimen increases with the number of applied cycles and then stabilizes after a certain number of cycles. In this study a novel “peak-temperature point” approach was identified as the most suitable methodology to determine the fatigue limit for a class of composite materials. The paper also sheds some light on how a suitable approach can be chosen to uphold the economic aspect of the self-heating methodology. The purpose of the present paper is to validate this approach for an impacted laminate. [ABSTRACT FROM AUTHOR]

Fatigue design optimization of composite material structures is limited by the classical approaches used, derived from knowledge based on metal fatigue. Other approaches exist to describe damage mechanisms of composites but they cannot always be applied at the structure scale because of their complexity. However, assumptions can be made in the case of beam structures to reduce the structural investigation at the section scale. With these assumptions this paper proposes to compare a progressive fatigue damage model written at the ply scale to the normative approach for the assessment of wind turbine blade section design. It is shown that the normative approach is very conservative and the progressive fatigue damage model provides very useful information to understand damage propagation at the structure scale. [ABSTRACT FROM AUTHOR]

The full estimation of the fatigue lifetime of a given material is needed for the industrial structures sizing. However, it requires time-consuming, expensive fatigue testing campaigns and a huge number of samples. An alternative experimental procedure is based on the monitoring of the “self-heating” properties. The aim here is to correlate the fatigue limit with a change of thermal behavior. The main advantage of such tests is that they only require few samples and are constituted of a limited number of mechanical cycles. Thus, self-heating tests lead to an accelerated estimation of the endurance limit. The purpose of the present paper is to validate this approach for carbon/thermoplastic composite materials. [ABSTRACT FROM AUTHOR]

This paper proposes a method for on the fast fatigue limit estimation for composite materials using a simulation of a self-heating test. The experimental method based on the material self-heating was successfully applied for composite materials and allows to determine a material’s endurance limit in a few hours. In order to increase the potential of this experience, the thermomechanical modelling is proposed with the precise description of the intrinsic energy dissipation. The rise of material’s temperature is linked with development of plastic strains, material damage, viscoelastic proprieties of polymer matrix and intro-crack friction. Therefore, the collaborative behaviour model including the hysteresis loops is used to represent the visco-elastoplastic damage composite behaviour. The collaborative model consists of two sub-models. The first one describes an envelope of the loading curves and insures the computation of elastic and the in-elastic strains as well as the in-ply damage. The second part deals with modelling of hysteresis loops during unloading path using a fractional derivative approach. Just a few parameters are required to represent the hysteresis loops. Using a proposed modelling, the dissipation due to the in-ply damage propagation, the material hardening and the viscoelastic effects can be precisely calculated. The fatigue limit is determined by using thermodynamic simulation the quasi-static cyclic test with the dissipation measurements as an equivalent to self-heating test. The method is validated for composite materials with thermosetting and thermoplastic matrixes. [ABSTRACT FROM AUTHOR]

Short-fiber reinforced parts show a distinct anisotropic behavior, caused by the alignment of the fibers during the injection molding process. The injection molding simulation provides the local probability distribution of the fibers (orientation tensor). By applying multi-scale material models it is possible to estimate the local anisotropic stiffness. This leads to considerable more accurate results in a subsequent FEA as with isotropic approaches. This is true even if higher temperatures lead to local plasticity. Tools that enable this integrative simulation approach have been established in the last years. To account for the anisotropic fatigue behavior an interpolation of fatigue strength at a discrete fiber orientation distribution is often used by estimating the anisotropic stiffnesses in direction of the orientation tensor principal directions. This is in most cases not appropriate. In the paper an approach is described that uses a so-called Master SN curve concept which estimates SN curves for varying local fiber orientation distributions. For the application case of high temperatures and local plasticity several enhancements were implemented and tested. The methodology is verified at the example of an oil-filter system under pressure at elevated temperature. [ABSTRACT FROM AUTHOR]

The paper describes the application of probability approach when assessing fatigue life of structures. The case study includes an assessment of two components of the rear axle of the trolleybus. The predicted fatigue life distribution functions were compared with service data. The calculations helped to identify and prevent fatigue cracks and fractures. [ABSTRACT FROM AUTHOR]

For security requirements, no fatigue failure of axles is admitted in railway industry. Design process of axles must ensure that there is no crack initiation during its life. Maintenance inspections guarantee that no defect initiates critical propagation of fatigue cracks. In order to remove surface defects, wheel grinding is realized during maintenance task. The present paper addresses a lifetime comparative study of an axle with and without grinding operation. The goal is to investigate the influence of the grinding parameters on the lifetime of axle. In the first part of the paper, the context of maintenance of railway axle is briefly described and the grinding process is presented. The grinding process modifies the roughness, the microstructure of the surface and induces residual stresses: some experimental results are presented. In the second part, the case of a ground axle is considered without defect. A study of the effect of the grinding process on the lifetime of fatigue samples is presented. In the third part, the case of a ground axle is considered with defects. In this case, a study of the effect of the grinding process on the lifetime is presented for different types of defects. Fatigue tests results on specimens are presented. Numerical simulations results for lifetime evaluation are also presented. [ABSTRACT FROM AUTHOR]

In the automotive industry, forged steels are commonly used for powertrain components such as gears, axles or crankshafts. In order to minimize wear and increase fatigue strength, these mechanical engineering parts are usually surface-hardened. The surface heat treatment leads to a significant change of the local material properties in the heat effected zone of the surface area. This paper addresses an effective two-layer model for evaluating fatigue strength of surface hardened components based on local stresses. Hence, one layer represents the induction-hardened surface and the second characterizes the base material. The aim of this elaborated method is a more reliable computational estimation of fatigue life among other assessments based on technological benefit factors for components designed for the high cycle fatigue (HCF) regime by taking into account local material properties, defects and residual stresses. In order to verify the presented method and to determine the local manufacturing process-dependent fatigue strength, specimens are extracted from highly stressed component areas considering forged grain structure. The sample notch shape represents typical notch types in mechanical engineering parts regarding form factor, stress gradient and highly stressed volume. The idea behind the fatigue tests is to study material samples exhibiting a comparably minor residual stress condition in both hardened and unhardened condition to separate the cause variables residual stresses, strength of base material and martensitic phase on fatigue strength. Compared to the unhardened base material, the fatigue tests at different stress ratios revealed higher fatigue strength within low and high cycle fatigue of the martensitic material. Considering these input data in combination with the fatigue strength of each material section, the layer approach enables a more reliable local fatigue assessment among other fatigue evaluation methods based on technological benefit factors. [ABSTRACT FROM AUTHOR]

The new standard of strength proof related to mechanical environment – design and implementation of environmental tests - includes new methods of assessment and synthesis of mechanical stresses. This paper proposes to remind the innovations and to constitute a constructive approach, based on their implementation and on the first experiences. The new standards contain new estimators of fatigue damage spectra and shock response spectra. In particular, the major novelty includes a statistical estimation for a given risk of overtaking of the stresses extrema and the damage extrema, which are computed from the measures performed on a duration much shorter than the in service real one. The purpose of these standards is to insure the mechanical design taking into account severe environments which may not have been measured. The authors propose to recall the fundamentals and to perform an analysis based on comparative results. Especially, will its use make the products more reliable? Will the use of these standards become widespread? [ABSTRACT FROM AUTHOR]

There are three major methods to verify the durability characteristics of a new designed leaf spring. These are simulation, test bench and rough road testing. Simulation is a rapid approach to find out the very first results for the assessment of the design. Test bench uses a pre-defined load program to estimate the lifetime of the leaf spring. It takes more time than simulation and is more costly. Rough road testing covers a complete endurance run for the whole heavy duty truck structure which is very costly and takes a very long time to accomplish. The aim of this paper is to reduce the time and the cost of the development procedure of a new designed leaf spring. The most efficient way to reach this goal is to correlate the results of the testing and simulation, so that, it would be possible to release new designs mostly depending on the simulation which is the fastest and the reasonable way to reach a final evaluation. A new designed leaf spring, with two leaves, is simulated in finite element analysis with the loads from multi body simulations in order to reach a fatigue life assessment; is tested in the test bench with the pre-defined loads from the rough road; is mounted to a complete truck structure to run a full rough road truck program to reach the final evaluation. In this paper, these three durability assessment techniques are compared and correlated with each other as a main scope. Additionally, the simulation methodology, the structure of the test bench and the procedure of the rough road testing are given in details. [ABSTRACT FROM AUTHOR]

In the last decade, the heat energy dissipated in a unit volume of material per cycle (the Q parameter) has been adopted by the authors as a fatigue damage indicator of metallic materials. The advantage of using such a parameter is that it can be readily and in-situ measured at a point or a component undergoing fatigue solicitations. Geometrical, mean stress and variable amplitude (limited to two stress-level tests) effects have been successfully analysed by using the Q parameter. Concerning geometrical effects, approximately 160 experimental results generated from constant amplitude, completely reversed, stress- or strain-controlled fatigue tests on plain or notched hot rolled as well as cold drawn stainless steel specimens have been rationalised. Afterwards, the heat-energy based approach was extended to include the mean stress effect, by using a thermodynamic fatigue damage variable that combines two parameters, i.e. Q and the thermoelastic temperature achieved by the material at the maximum stress of the load cycle. Finally, Q was used to rationalise two stress-level fatigue test results, by using the Q-based fatigue curve combined with Miner’s rule. In this paper, the theoretical background and the application of the energy-based approach are reviewed in order to analyse all previously mentioned effects, focusing mainly on the mean stress and the variable amplitude, two stress-level effects. [ABSTRACT FROM AUTHOR]

In the case of Crane industry sector, with high requirements of security and performance, slewing rings are important parts of equipment and manufacturers need to guarantee their mechanical strength and durability. Since more than ten years, on demand of industrial groups, CETIM is working on slewing rings in the fields of tests, design and calculations. For the last couple of years, extensive work has been done to develop a calculation methodology giving access to forces in balls of rings. These forces, used as input of local non-linear finite element models including contact definition, allow stress state calculations in tracks of rings. Fatigue analysis is then conducted based on appropriate criteria taking into account the complex multiaxial stress state and the gradient of material properties due to the surface treatment of the tracks (induction hardened parts). Parametric calculations have been made in order to estimate the influence of some parameters such as contact angle of the balls, geometric conformity, mechanical clearance and depth of treated material. Results allow identifying most important parameters and show how these parameters influence the damage location on the slewing rings, with good correlation with physical observations on damaged components. A synthesis of this long term work is presented in this paper. [ABSTRACT FROM AUTHOR]

Modelling fatigue assessments for welded components is a challenging task as to achieving accurate results. Several influence factors reduce accuracy and often the difference between the calculated and the effective fatigue life is located in the range of factor 10 and above. This conference paper presents two advanced methods which allow the achievement of better accuracy. The main aspect consists in taking the geometry into account, a procedure that leads, though, to the need of adapting the existing methods for fatigue assessment. One of these advanced methods is used to examine a detail which has been welded with different welding processes and on different positions. [ABSTRACT FROM AUTHOR]

In fatigue design of welded joints according to the notch stress intensity factor (NSIF) approach, the weld toe profile is assumed to be a sharp V-notch having tip radius equal to zero, while the root side is assumed to be a pre-crack in the structure. The Peak Stress Method (PSM) is an engineering, FE-oriented method to estimate the NSIFs starting from the singular linear elastic peak stresses calculated at the V-notch or crack tips by using a coarse FE mesh. The element type is kept constant and the average element size can be chosen arbitrarily within a given range. The method is used in conjunction with Ansys software. The FE meshes are claimed to be coarse in comparison to those necessary to evaluate the NSIFs from the local stress distributions. Two-dimensional as well as three dimensional FE analyses can be adopted to apply the method. By using the averaged Strain Energy Density (SED, which can be expressed as a function of the relevant NSIFs) as a fatigue strength criterion, a so-called equivalent peak stress is defined to assess either weld toe or weld root fatigue failures in conjunction with a properly calibrated design curve. After presenting the theoretical background of the method, the paper presents a review of applications of the PSM relevant to steel welded joints under uniaxial as well as multiaxial fatigue loadings. Because of the relatively coarse FE analyses required and simplicity of post-processing the calculated peak stresses, the PSM might be useful in the everyday design practice. [ABSTRACT FROM AUTHOR]

In industry with fatigue strengthening concern, there are as many ways to make an FE seam weld idealization as factories involved in these types of simulations. Tens of ways to model a seam weld are available as soon as it is necessary to get out of direct connection assumption and if it is needed to take into account local weld stiffness and secondary bending effect of the fillet weld. Then it becomes mandatory to be able to discriminate such idealization processes while evaluating associated life prediction accuracy and industrial idealization efficiency (automation). This concern leads the idea to create a French industrial workgroup including CETIM and about 20 industrial companies, members of the “Mobile Machinery Program Committee”. The main goal of this collaborative project being to challenge well documented and most promising seam weld idealization models (with associated methods) to converge at the end towards the most capacitive ones (with better results on given fatigue metrics). As a first part of the multi-partner project work, a complete and precise technical review was achieved, giving a state of the art of the idealization models and methods available. Then the workgroup started extensive comparisons between well documented fatigue tests on seam welded components and associated FEA for some retained models and methods (Fayard, Lohr, IIW Hot Spot Stress, Notch Stress). Several components were considered, with more than 100 fatigue test results. This paper presents most of the obtained results, the Round Robin being still on-going. Preliminary results comparisons demonstrate general applicability of classical methods introduced in the standards or recommendations, these being also in most cases conservative. Results of this work aim to help choosing the right methodology, depending of the seam weld configuration and the in service loadings. It is also intended to try building partnerships with FE software editors to include most efficient methodologies in an automated way, making less tedious the seam weld modelling task on huge chassis frames. Small and medium factories should then reach an efficiency gain and improved accuracy level when building their virtual seam welded frames with new automated scripts integrated in their own FEA solutions. [ABSTRACT FROM AUTHOR]

The electromagnetic pulse technology (EMPT) is a joining process similar to the explosion welding. In the process, a flyer-sheet is accelerated towards a target-sheet using electromagnetic fields. During impact high normal and lateral contact forces are generated which join the sheets on an atomic level. This process can be automated for joining thin sheets and is therefore especially suited for mass production, e.g. in the automotive industry. The resulting joints are not comparable to ones made by common MIG/MAG or laser welding processes since no heat is induced. This leads to the question if the standard approaches to assess the weld in terms of their fatigue behavior can be used also and if a reliable fatigue assessment can be achieved. In the paper, the fatigue strength of EMPT-welded connections under constant amplitude loading is presented. Common assessment approaches like the notch stress approach are applied to assess the fatigue life. A comparison between numerically derived fatigue life and experimental tests shows a good agreement and proves the applicability of established approaches. [ABSTRACT FROM AUTHOR]

The design of parts and structures in the vehicle development process is highly influenced by strength and stiffness requirements. Under cyclic loading a change in the local stiffness of joints can be observed which motivates analyses in order to tackle stiffness changes in structures. The fatigue and stiffness behaviour has been obtained for several joining techniques and material combinations: spot and seam welds, remote laser welds and high velocity bolting for steel and/or aluminium partner sheets. Specimens under shear and peel loading as well as hat profiles under torsion have been tested under constant amplitude loading. Quasi-static tests and micrographic evaluations have been conducted in order to determine material parameters and the setup of FE models. Online stiffness measurements during fatigue life have been performed. In this paper an approach to describe degradation in specimens representing a joint detail is presented. The stiffness degradation curves for the various joining techniques are compared and a numerical description of the stiffness degradation behaviour for further simulations is derived. The concept of simulating stiffness changes in conventional joining techniques is introduced. First numerical analyses of stiffness changes in spot welded specimens are presented. Several sensitivity analyses, e.g. with regard to R-ratio or loading amplitude, are performed in order to check the numerical stability of the implemented method. [ABSTRACT FROM AUTHOR]

During a still running European Project the feasibility of vehicle light weighting technologies for the manufacturing of light urban electric vehicles with new standards of mechanical performance will be demonstrated. One of the innovative technologies of the project, the Electromagnetic Pulse Technology (EMPT), which is a high speed crimping method, will be applied for joining of particular structural parts of the body, especially to join different lightweight materials such as Al- or Mg-tubes and Al- and Mg-cast or forged nodes. Current heat-intensive joining processes are faced with a number of drawbacks and “cold” classical adhesive techniques require cost-intensive preparation methods plus long curing times and show design uncertainties in terms of mechanical strength. Hence, joining of dissimilar materials is presently not widely used. The Electromagnetic Pulse Technology (EMPT) is an innovative approach for joining particular structural parts, where different lightweight materials can be joined without any significant heat input by a fast process. Therefore, this technology is determined as a high efficiency joining process from the quality and the energetic point of view, with virtually no loss of energy in form of heat. Presently, no design relevant characteristic values of such joints, neither endurable stress amplitudes (fatigue) nor stiffness behaviour of the connection during cyclic loading, are available. Hence, the reliability of such EMPT joints has to be validated with regard to fatigue and stiffness behaviour in order to guarantee a durable connection under typical service loading conditions. This paper will present first fatigue testing results for aluminium tube joints of EN AW-6082-T6 with a diameter of 40mm. Within this investigation the endurable strength and stiffness behaviour of EMPT joints will be determined in order to validate the performance of the Electromagnetic Pulse Technology for reliable applications under cyclic loading for e. g. urban electric vehicles. [ABSTRACT FROM AUTHOR]

The 3rd Edition of API 579-1/ASME FFS-1 2016 Fitness-For-Service includes a new Part 14 dedicated to fatigue assessment. An important section in this part covers the fatigue assessment of welded joints. In this paper, an overview of the fatigue methods for welded joints is provided and extensions are recommended. First, an overview is given of the classical fatigue method used in the ASME B&PV Code based on smooth bar fatigue curves in conjunction with a fatigue strength reduction factor. In addition, the mesh insensitive structural stress method is outlined using an equivalent stress parameter based on fracture mechanics considerations in conjunction with a master S-N curve based on the analysis of over 2000 high and low cycle S-N test data. The resulting master S-N curve approach is applicable to high cycle fatigue and low cycle fatigue if a Neuber correction is introduced. In this paper, a new structural strain method is presented to extend the early structural stress based master S-N curve method to the low cycle fatigue regime in which plastic deformations can be significant while an elastic core is present. With this new method, some of the inconsistencies of the pseudo-elastic structural stress procedure can be eliminated, such as its use of Neuber’s rule in approximating structural strain beyond yield. The earlier mesh-insensitive structural stress based master S-N curve method can now be viewed as an application of the structural strain method in the high cycle regime, in which structural strains are linearly related to traction-based structural stresses according to Hooke’s law. Thus, both low cycle and high cycle fatigue behavior can now be treated in a unified manner. In the low-cycle regime, the structural strain method characterizes fatigue damage directly in terms of structural strains that satisfy a linear through-thickness deformation gradient assumption, material nonlinear behavior, and equilibrium conditions. A PVRC Joint Industry Project is currently sponsoring work on the structural strain method that will lead to its incorporation in the next edition of API 579-1/ASME FFS-1. [ABSTRACT FROM AUTHOR]

The lifetime extension of the nuclear power stations is considered as an energy challenge worldwide. That is why, the risk analysis and the study of various effects of different factors that could potentially represent a hazard to a safe long term operation are necessary. These structures, often of great dimensions, are subjected during their life to complex loading combining varying mechanical loads, multiaxial, with non-zero mean values associated with temperature fluctuations and also PWR environment. Historically, the methodology for fatigue dimensions of the Pressurized Water Reactor components (PWR) (ASME, RCC-M, KTA, …) is based on the use of design curves established from tests carried out in air at 20°C on smooth specimens by integrating safety coefficients that cover, among other parameters, the dispersion of tests associated with the effects of structures. Based on more recent fatigue data (including tests at 300°C in air and PWR environment, etc…), some international codes (RCC-M, ASME and others) have proposed and suggested a modification of the austenitic stainless steels fatigue curve combined with a calculation of an environmental penalty factor, namely Fen, which has to be multiplied by the usual fatigue usage factor. The aim of this paper is to present a new device "FABIME2E" developed in the LISN in collaboration with EDF and AREVA. These new tests allow quantifying accurately the effect of PWR environment on semi-structure specimen. This new device combines the structural effect like equi-biaxiality and mean strain and the environmental penalty effect with the use of PWR environment during the fatigue tests. [ABSTRACT FROM AUTHOR]

The paper deals with the process of crack growth in a layered material made by explosive welding from AA2519 aluminum alloy and Ti6Al4V titanium alloy. The tests involved loading CT type specimens parallel to the weld surface so as to cause simultaneous fatigue crack growth in both layers. Independent optical measurement of the crack growth lengths enabled comparison of the crack growth behavior for both layers and relating them to the results of a crack growth analysis performed by the compliance method with the use of a COD extensometer and FEA crack length analysis. Tests of crack growth lengths by the compliance and FEA methods were also performed in a liquid nitrogen which made it possible to compare the crack growth behavior in ambient temperature and cryogenic temperature. [ABSTRACT FROM AUTHOR]

In the automotive light-duty passenger vehicles, double dry clutch provides high comfort and fuel efficiency to passengers with automated gear box. Its functional performance and quality depends on its diaphragm spring. Fatigue analysis on this component and correlation is quite complex because of several manufacturing processes involved like stamping, heat stabilization and shot-peening. The procedure to predict the diaphragm fatigue strength is described in the paper; also it integrates the new simulation softwares capabilities to handle the process effects for evaluation of diaphragm. This paper outlines the different simulation stages involved to access the fatigue assessment on diaphragm spring; also it is done at various life situations of vehicle: normal, parking, overloading conditions. A great attention is paid for correlation through measurement fitting in simulation. Between each manufacturing process simulation, the deformed shape and its residual stress-strain data are mapped using customized scripts. After the process simulations, fatigue actuation on diaphragm is done for new, semi-worn and worn positions of clutch. Miner’s damage and its summation are done at each critical point in diaphragm to determine its total life under nominal design. [ABSTRACT FROM AUTHOR]

Induction hardening as common heat treatment process for highly-stressed automotive components significantly affects the surface layer properties leading to a compressive residual stress condition and a local hardening of the material. The beneficial effect of the post-treatment is generally well investigated and already implemented in industrial applicable guidelines by considering nominal fatigue strength enhancement factors. However, as the fatigue strength improvement essentially depends on the applied manufacturing process parameters, the resulting local material properties and the local load stress distribution, an elaborated numerical fatigue assessment procedure based on a manufacturing process simulation of a notched round specimen is presented in this paper. Thereby, a two-dimensional axi-symmetric model is set-up, whereby the inductive heating process is performed in COMSOL® and the subsequent quenching process in SYSWELD®. The resulting axial residual stress condition at the notch area of the specimen reveals a sound accordance to X-ray measurements. Finally, a local fatigue strength assessment based on the local strain approach is shown. Herein, manufacturing dependent residual stress states are considered as mean stresses on the basis of the damage parameter by Smith, Watson, and Topper. The estimated fatigue data points agree well to results of four-point bending fatigue tests, which basically prove the applicability of the presented fatigue design methodology. [ABSTRACT FROM AUTHOR]

Tubular arch bridges are susceptible to fatigue problems due to stress concentrations, welding imperfections and tensile residual weld stresses. These bridges are composed of circular hollow section profiles welded together in tubular joints. This paper describes the determination of residual weld stresses in T-joints with the incremental hole-drilling method. The residual stress distribution can be used to determine fatigue crack behavior and fatigue lifetime more precisely. The incremental hole-drilling method is used to measure residual welding stresses on two similar T-joints. Experimental residual stress measurements were performed with the aid of the RS-200 milling guide. Strain gauge rosettes are attached to the test surface and with the milling guide, a small hole is drilled through the center of the strain gauge rosette. Strains at incremental depths are measured and the residual stresses are calculated according to ASTM E837-13a. A comparison is made between residual stress distributions obtained with finite element simulation and the experimental measurements. The distributions from finite element simulation show tensile yield stresses close to the weld while the experimental measurements indicate tensile yield stresses only in the axial direction of the primary tube. In all other cases, the residual stresses are tensile within 50% of yield stress or even compressional. However, more measurements on similar test specimens are necessary for a reliable residual stress distribution. Knowledge of the residual stress distribution is essential to accurately estimate the crack development under fatigue loads. In future research, the residual stresses can be used to study the influence of residual weld stresses on the fatigue lifetime and improve the design of steel tubular joints in arch bridges. [ABSTRACT FROM AUTHOR]

This paper presents experimental investigation and numerical modeling of the effect of compressive residual stress on the corrosion fatigue life of a low carbon steel. A fatigue life test methodology based on double notched tensile test specimens is proposed. A new plasticity model is proposed for accurate simulation of compressive residual stress and calibrated to experimental stress-strain curves obtained for low carbon steel. The proposed model is implemented as a user-material in the ANSYS Workbench Finite Element Analysis program and utilized in plastic analysis and fatigue assessment. Corrosion fatigue test results are discussed and compared to numerical predictions. [ABSTRACT FROM AUTHOR]

Flexible riser systems offer operators a robust method of producing oil and gas fields in harsh environments. Systems are currently designed using a mixture of local and international standards such that they can withstand conditions with a sufficient margin of safety. Flexible pipes have been installed for water depth exceeding 2500m. The application of reliability methods to determine the design of offshore systems such as jackets and ship hulls is well developed and has a long and successful track record. Flexible risers are subjected to the same random environmental loads. While probabilistic methods have been explored, they have yet to be applied in any meaningful manner to the fatigue limit state. How to account in the most robust manner for uncertainties within the loading has become critical for deriving cost effective and robust design rules for flexible risers. Especially the layer of the flexible riser bearing the tensile load, named tensile armours, is critical in the design in many of the deep-water developments. In this paper, multiple structures designed for west of Africa and the North Sea are investigated through a reliability method. Typical Uncertainties within the global riser motions, the local stress computations and in the stress-life curve resistance are accounted for. Demonstration is made that for the same uncertainties the variables influencing the reliability of the structure differ. Finally, the comparison with actual international design rules is made through the value of the safety factor applied on the design life. [ABSTRACT FROM AUTHOR]

Numerical simulation is more and more used in automotive industry to reduce design time and cost. Moreover, for high performance engines, the development of cylinder heads requires well known and adapted materials to ensure their reliability. The estimation of adapted fatigue criteria based on few experiments is thus an important challenge: to obtain more predictive model on more complex mechanical phenomena. This paper describes the methodology adopted by Renault to estimate fatigue life of a new aluminum-silicon alloy. A low copper aluminum-silicon alloy has been developed for a new generation of cylinder heads. Those kinds of alloys provide a good compromise between the two main failure modes encountered for cylinder heads: high cycle fatigue of water jacket and low cycle fatigue of fire deck. However, those materials are subjected to thermal ageing that can affect mechanical behavior, such as yield stress and hardening, but also fatigue mechanisms at higher temperatures. This article presents first the selected constitutive equations that introduce thermal ageing effect in a cyclic elasto-viscoplastic model. The low cycle fatigue criterion is then calibrated on the relevant database, which includes isothermal and non-isothermal tests. The fatigue criterion is a specific version of a classical model previously developed at Onera. The critical variables for the fatigue part are the stress amplitude and the mean stress, both of them being normalized by an ultimate stress which depends on temperature and ageing state. Finally, the constitutive and damage models have been applied on 3D cylinder head numerical analysis. The paper proposes a brief comparison of those results with more classical simulations made on cylinder heads and highlights the perspectives offered by this new aluminum-silicon alloy. [ABSTRACT FROM AUTHOR]

Acoustic Induced Vibration (AIV) refers to the high acoustic energy generated by pressure-reducing devices that excite pipe shell vibration modes, producing excessive dynamic stress. Analysis of this risk is an important part of Asset Integrity Management systems as AIV can cause catastrophic piping failure. Existing guidelines address this risk through an analytical assessment. However, these methodologies are not fully known and input parameters are limited. Some limits to the guidelines are pointed out with recommendations to improve them. The approach presented for identifying AIV damage is based on a dynamic stress evaluation at pipe discontinuities (welded connections and supports). This evaluation is performed through a fluid-structure coupling Finite Element Analysis. Pressure fluctuations inside the pipe are predicted and coupled with a pipe structural analysis. This methodology is provided with its validation through measurement on an actual AIV field case, corresponding to a crack initiation due to AIV on an FPSO flare network tail pipe. To conclude the paper, the method is then applied to quantitatively assess the mitigation actions’ efficiency on an actual case. Different solutions have been individually tested to end up with a final solution that reduces the damage to acceptable levels in the most cost-effective manner. [ABSTRACT FROM AUTHOR]

As the number of heavy railway traffic load increased, concern over the accurate and actual fatigue damage of the bridge is intensified. Especially for bridges which were designed for light traffic load. The fatigue damage assessment of steel bridge connections is usually based on notion of uniaxial S-N curves given in the codes of practice. Until now, there is no consensus on a method which can precisely consider non-proportional multiaxial loading. The objective of this paper is to examine the applicability and appropriateness of the critical plane approach-based C-S criterion to perform the fatigue damage assessment in welded connections in railway steel bridge. A regular U trough railway steel bridge is analyzed using finite element software ANSYS 17.2 for standard railway traffic. The averaged principal stress directions determined through appropriate weight functions are used to orient the critical plane. Prediction of fatigue damage is performed through an equivalent stress represented by a quadratic combination of the normal and the shear stress components acting on the critical plane. Applicability of the C-S criterion is studied by assessing the fatigue damage of critical welded connections and comparing with the λ - coefficient and cumulative damage method calculated according to Eurocode EN1993-1-9. [ABSTRACT FROM AUTHOR]

Fatigue lifetime estimation of load bearing parts of construction is a key factor in a design of technique used for long term operation. Complex loading in combination with complex geometry of the most loaded parts represents only one of many problems that engineers have to deal with. One of the most commonly used approaches how to deal with this problem is to use the technical standards. This approach, despite its indisputable advantages (clear and comprehensible steps of calculation), has several significant shortcomings (non-economical oversized design). In this paper we propose procedure of how to estimate fatigue lifetime of construction parts that are loaded with random operational loading. The result of proposed procedure is distribution function of fatigue lifetime which takes into account the complex geometry of the designed part and random character of the complex loading (multiaxial stress state) in a hotspot. This approach is then demonstrated on fatigue lifetime estimation of bearing pin of a console manipulator loaded by random operational loading. Loading process was obtained using set of strain gages. The measured loading process was then transformed into stress histories in critical hotspot using FEM. Method of processing the stress loading histories in critical hotspot into a form usable in combination with hypotheses for fatigue damage calculation under multiaxial stress states is presented. [ABSTRACT FROM AUTHOR]

In this paper, the results of the fatigue tests of the P92 and 15CH2NMFA steels are presented and discussed. The fatigue S – N curves were obtained by means of both standard and miniature test specimens. The Small Fatigue Test (SFT) specimens were manufactured partially by machining and also by waterjet cutting. The fatigue tests were performed on Amsler 10 HFP 5100 ZWICK//Roell high-frequency pulsator at room temperature and R = 0,1 and R = -1 cycle asymmetries. The results obtained on standard and SFT specimens are compared and in case of P92 steel are also compared the two methods of SFT specimens manufacturing. In case of 15CH2NMFA steel, the results of standard and SFT specimens are in a very good agreement both within the time limit fatigue range and the fatigue limit. After taking the stress concentration of SFT specimens into consideration, the results of traditional fatigue test samples and SFT samples are similar. In case of P92 steel, the leaning branch of S-N curves is much steeper for SFT specimens and the fatigue limits lower than it could be expected after the stress concentration is taken into account. The fatigue limits for equal cycle asymmetry show the same ratio of standard to SFT fatigue limits, for R = 0,1 it is 1,31, for R = 1 it is 1,32. This very good agreement can be used for the evaluation of fatigue behaviour of P92 steel by means of SFT specimens. The comparison of the two ways of SFT samples manufacturing revealed a scatter of fatigue test results, nevertheless the fatigue limits differ by 5 MPa only, so that even the influence of the manufacturing seems to be negligible. [ABSTRACT FROM AUTHOR]

An extensive experimental investigation of different temperatures and strain rates has been carried out on aluminum alloy Al319-T7. It is found that elevated temperature tends to decrease the strength in tensile and cyclic tests, whereas increasing strain rate appears to improve the strength, and in strain-controlled isothermal fatigue tests, higher temperature results in shorter fatigue life for a given stress amplitude. In addition, increased strain rates are found to improve the fatigue life in high-temperature tests, while their effect is negligible in room-temperature tests. In-phase (IP) and out-of-phase (OP) thermo-mechanical fatigue (TMF) tests with and without dwell time are also conducted in this paper. The results reveal that for the same applied total strain amplitude, OP tests, owing to their larger mechanical strain amplitude, are more critical than IP tests. Furthermore, stress relaxation happening in dwell time will help to increase the fatigue life, compared to those tests without dwell time. [ABSTRACT FROM AUTHOR]

The Austrian Climate and Energy (CEM) model regions are facing energy transition towards a greater share of renewable energy sources in the final electricity mix. To guarantee the resilience of the CEM socio-economic and regional systems, an integrated approach towards electricity generation and transmission is necessary. The changing architecture of electricity generation is causing new challenges to the transmission grids to adapt. The cascading risks of existing and emerging risks for electricity transmission grids can lead to power outages and even blackouts. This paper argues about the need of a multi-risk approach towards risk assessment and risk governance for resilience of CEM regional electricity systems. It also discusses a multi-risk governance perspective as a tool to strengthen resilience of urban socio-economic systems against electricity blackouts. Based on extensive dialogue with stakeholders from the CEM regions over the last two years the paper develops recommendations for inclusive and participatory risk governance process. The data collection included contributions of stakeholders from public and private sector, as well as academia and civil society. The analysis of data was done in light of possible stakeholders and public engagement into decision-making processes on risk mitigation measures and strengthening of electricity infrastructure of the CEM regions in Austria for resilience in the process of energy transition. [ABSTRACT FROM AUTHOR]

Landslides are one of the major natural disasters that occur in Sri Lanka resulting in loss of lives and severe damages to livelihoods and property. Landslide hazard mapping project was launched to study and identify the distribution of landslide potential in central highland of Sri Lanka. Spatial distribution of risk buildings locate in very high and high landslide hazard prone areas are being identified through 1:10,000 scale landslide hazard maps prepared for the lowest administrative units called Grama Niladari Divisions. A building survey is carried out in housing units, commercial/institutions, religious places and schools, which are located in very high and high hazard landslide prone areas of the Badulla District. This paper presents the results of the building survey carried out in housing units locate in very high and high landslide hazard prone areas of Hali-ela D.S Division in the Badulla District. The empirical evidence revealed ten pertinent issues, livelihood of the families rely on lands in landslide prone areas; designing of houses without professional support; construction of houses without approval obtained from relevant authorities; construction of houses without obtaining landslide clearance certificate; construction of houses on steep slope (>31°) terrain; change of land morphology for construction of houses; presence of tell-tale landslide signs at the vicinity of houses; having no drainage system to discharge rain water; possibility of access road to the settlement damage by disaster; inadequate instructions to inhabitants on disaster preparedness; and housing units built without the support of professionals, to protect against landslide hazard and reducing landslide disaster risks. [ABSTRACT FROM AUTHOR]

While developing a housing project the concept of resilience needs to be reflected in the whole process rather than the resulting product; because both the extent of loss or damage and recovery from a disaster depend on victim’s building practices, preparedness, effective response and most importantly acknowledgement of the risks. The design process, therefore, should be derived from beneficiaries’ economy, social behaviour, settlement and dwelling morphology, and inclusive of their participation. Any rehabilitation initiative devoid of empowerment of victims may result in unsuccessful endeavour. As Bangladesh is highly disaster prone and projected as one of the worst victims of climate change, resilience inevitably becomes a part of the housing process. The Purpose of this write up is to demonstrate some concepts of resilient habitat for cyclone prone areas of Bangladesh. These concepts are derived from literature review, observation study and interviews with the inhabitants and stakeholders. It emphasizes the inclusion of indigenous measures as well gender dimensions. Technologies that may promote local skill and facilitate women’s involvement in maintaining and preparing the house are encouraged. As a whole, the paper attempts to manifest local response experiences and outline some points to look into the way of reducing disaster impacts and build back better. [ABSTRACT FROM AUTHOR]

Environmental change and natural events can impact on multiple dimensions of human life; economic, social, political, physical (built) and natural (ecosystems) environments. Water distribution networks cover both the built and natural realms and are as such inherently vulnerable to accidental or deliberate physical, natural, chemical, or biological threats. An example of such threats include flooding. The damage to water networks from flooding at the building level can include disrupted supply, pipe damage, sink and sewer overflows, fittings and appliance malfunctions etc. as well as the consequential socio-economic loss and distress. It has also been highlighted that the cost of damage caused by disasters including flooding can be correlated to the warning-time given before it occurs. Therefore, contiguous and continuous preparedness is essential to sustain disaster resilience. This paper presents an early stage review to: 1. Understand the challenges and opportunities posed by disaster risks to critical infrastructure at the building level. 2. Examine the role and importance of early warnings within the smart systems context to promote anticipatory preparedness and reduce physical, economic, environmental and social vulnerability 3. Review the opportunities provided by smart water microgrid/net to deliver such an early warning system and 4. Define the basis for a socially-integrated framework for resilience in building water networks based on smart water micro grids and micronets. The objective is to establish the theoretical approach for smart system integration for risk mitigation in water networks at the building level. Also, to explore the importance and scope integration of other social-political dimensions within such framework and associated solutions. The findings will inform further studies to address the gaps in understanding the disaster risks in micro water infrastructure e.g. flooding, and; to develop strategies and systems to strengthen disaster preparedness for effective response and anticipatory action for such risks. [ABSTRACT FROM AUTHOR]

This paper examines the long term impact of relocation on tsunami affected families who were resettled far from the city of Galle, Sri Lanka due to re-imposed buffer zone regulations. The study adopted a longitudinal study design where the researcher collected qualitative data from selected families for a period of ten years by using in-depth interviews from four settlements in the Akmeemana Divisional Secretariat (Green Village, Salzberg, China Charity and Tea Garden). It is evident from the analysis that relocation has been merely considered to be a donation of a house to a family displaced by the tsunami than having considered relocation as a process when planning and implementing these projects. Thirteen years after involuntarily relocating families into unplanned settlements some of them have been forced to move back in to the buffer zone as they were not able to successfully cope with various stresses and risks generated by involuntary relocation. As a consequence, the host community were encouraged to purchase or rent these houses vacated by tsunami beneficiaries for a reasonable sum. The researcher concludes by stressing the importance of people centric policy guidelines for the sustainable relocation of disaster induced displacement in Sri Lanka. [ABSTRACT FROM AUTHOR]

This study focused on the Disaster Risk Reduction and Management of Tarlac City. The city disaster risk reduction and management structure; the identified hazards and evacuation areas; the Tarlac City DRRM Plan in four thematic areas as identified in the NDRRM Plan; the CDRRMO vehicles, equipment, and resources; and the community based responders are presented in this paper. The following conclusions are reached based on the gathered information and data. The CDRRMC and CDRRMO are established and functioning as to their mandate, based on the certificate of recognition given by DILG to the City Government of Tarlac regarding disaster preparedness. The structure of the CDRRMO is approved by the city council but lacks funding for filling up the identified positions. The CDRRMO has a hazard map with identified barangays prone to flooding, lahar flow, and earthquake. The thematic action plans of the City Government are aligned with the Sendai Framework for Disaster Risk Reduction. This is evident in the list of programs and projects in their action plans. The existence of community based responders shows that the City Government is extending support to the barangay level by training local officials on how to respond in times of disaster. [ABSTRACT FROM AUTHOR]

The Village Pasir Nan Tigo located in the sub-district of Koto Tangah, Padang city. Geographically, the village located in the coastal area and some areas in this village are separated by a river. Topographically, this area is flat, and there are no hills that can be used as a natural shelter. The village located in the Tsunami Inundation Area, where the population in this district should be immediately evacuated to a safe area if there is a tsunami warning from the government or large tsunamigenic earthquakes. However, due to the river that divides some areas, the refugees have to follow the main road in the village along the coastline before turning onto the highway of Padang and move towards a safe zone. The advice from the government is, they must run away from the seashore and get into the safe areas as quickly as possible. In other words, instead of moving towards the east of the city of Padang, the refugees must run to the south of the city. In this context, this study aims at assessing the evacuation route in this area by using Network Analysis. With the objective of reducing the number of fatalities in this village, the shortest path algorithm is applied to analyse the direction of movement, and the travel time communities need to get to a safe area of the tsunami. The results of closest facility analysis and service area analysis show that the horizontal evacuation method for Pasir Nan Tigo populations is ineffective or inaccurate, with the main reason; that the distance is very far. Therefore, the need for a vertical evacuation plan such as building a shelter is highlighted in this paper. [ABSTRACT FROM AUTHOR]

A resilient city is a sustainable network of physical systems, constructed urban form, and human communities. Traditional or vernacular built form evolves to achieve higher human comfort by using locally available building materials and construction technology and is more responsive to the geographic conditions. In contrast to the highly bureaucratized building process in modern built form, vernacular architecture is more climate responsive. A typical traditional building of earth emits fewer greenhouse gases, consumes less energy, and maintains a high level of internal thermal comfort. Resilient urban systems must also have resilient communities. Traditional built form results in the creation of social spaces, promotes adherence to socio-cultural value systems and imbibes a feeling of social cohesion. Modern construction techniques, greater energy consumption and the loss of diversity of architectural forms would have significant implications on urban resilience. The paper aims to trace the changing built form in a small settlement of West Bengal and the resultant loss of climate responsive and socially interactive spaces. Based on primary data sources and field observations, the paper also looks into the implications of the loss of such spaces on urban resilience and assesses the perception of the locals who prefer modernization of built form. [ABSTRACT FROM AUTHOR]

Growing trend of disaster-induced displacements and resettlements is alarming the world to address the consequences to retain the stability of the concerned countries. In order to reduce the causes and consequences of displacements, governments and other concerned entities involve in the process of resettlement in different scales. However, settlers complain of the large-scale resettlement schemes for their inability to meet long-term expectations. Adaptability of the built environment is viewed as one of the principle reasons for this criticism. Accordingly, this paper aims to explore the long-term adaptability issues face by the communities who live in resettlements. Resettlement is a process that introduces new built environment for the displaced community. This new built environment potentially redefines the social system as one interlinked with other subsystems of the community. However, following a fundamental change in the system, restoring the earlier equilibrium of a community requires certain basic conditions. Resettlement fails if the built environment does not provide these basic conditions. Failure in terms of built environment has been recorded in studies based on the inappropriate house design, insufficient infrastructure, inappropriate new environment, and alike. Based on several case studies, it is assumed that the process of resettlement in developing countries follows almost the same pattern as the results of similar resettlement cases that are shown in various pieces of literature reflect same issues. Therefore, in order to understand the process of resettlement in detail, selecting a particular developing country will give more focus to draw conclusions. Accordingly, Sri Lanka is selected as the study focus. The data collection technique that is used for this study is semi-structured interviews. These interviews were conducted among settlers in 3 different resettlement schemes in Sri Lanka. The interview results are analysed using content analysis. The outcome of this study shows the enablers and barriers in adapting a post-disaster resettlement which is necessary to identify in order to provide durable solutions. [ABSTRACT FROM AUTHOR]

Natural disaster has led to adversity resulted from its physical (immediate on-set) and social (long-term) impact. Physical impacts majorly involved human casualties and loss or damages to properties and infrastructure. Meanwhile, among social impacts to society are the psychosocial, socio-demographic, socioeconomic, and socio-politic disturbances. Reducing the risk and impact of the disaster therefore, requires various efforts to prepare and empower the community through the implementation of disaster risk reduction (DRR) during and after a disaster as it is proven that the community themselves are first responders when disasters strike. An excellent example would be the Kobe earthquake where most of the victims survived due to prompt actions taken by members of their community. This indicates that a well-informed community i.e. with high level of awareness and sound knowledge on disaster preparedness and mitigation played crucial role in preventing greater incident of human casualties and reduce socio-economic loss to the community. Therefore, building a resilient community has become part of DRR initiatives. Review of literature, however, suggests that there are gaps in implementation due to lack of understanding of resilient community concept and suitable community-based approach in promoting a community resilience spirit towards disaster. This paper is prepared to discuss the framework considerations for building disaster resilient community in Malaysia from three (3) perspectives of DRR namely; (1) resilient community’s main capitals; (2) key drivers to community resilience and; (3) key deliverables of disaster-resilient community. [ABSTRACT FROM AUTHOR]

The task of reducing disaster risks poses enormous challenges for international and local non-governmental organizations despite the immense assistance offered in reducing disaster risks and cushioning the effect of disasters. Among other issues responsible for the setback experienced is that of institutional constraints. ‘Institutions’ act as a fulcrum for achieving social norms that shape behaviour and actions within society via rules, professional ethics, standards, policies, regulations etc. Government establishments in the same organizational field - particularly those recognized to deliver public goods and services for disaster risk reduction often experience institutional constraints such as lack of clear policies and mandates to guide government institutions, lack of coordination between institutions, inadequacy in the required human capacity in public sector etc. These constraints often contribute to increased societal risk conditions. Where institutions are elements of governance, framing them also becomes a simultaneous attempt to manage risks to society. An overwhelming body of existing organizational behaviour literature affirms that organizations adopt practices or behave in a certain manner to gain access to resources and legitimacy for survival including under uncertain or complex circumstances when subjected to institutional pressures. Such pressures influence operational and strategic arrangements and has been discussed from a private sector organizations perspective. Against this background, little attention has been given to influence of institutional pressures on public sector organizations and scarcely from a disaster risk reduction perspective. The aim of this paper is to investigate the role of governance and influences of institutional pressures on public sector organizations from a disaster risk reduction perspective. This is achieved through reviewing literature on institutional theory to provide an understanding on the concept of institutional isomorphism and its effect on key issues such as goal ambiguity, professionalism and structuration as well as technical uncertainty. The implication for practitioners is that it offers background knowledge required for key players and professionals to design appropriate response strategies to isomorphic pressures to support institutional sustainability, encourage homogeneity for effective DRR delivery and fills the knowledge gap presented for further research. [ABSTRACT FROM AUTHOR]

Following increases in the frequency and magnitude of disasters over the past decades, continuous knowledge production and dissemination has become a crucial pathway for understanding disaster risks. The Sendai Framework provides guidance for various levels of governance and well lays emphasis on managing ‘disaster risks’. While a great deal of existing scholarship has contributed immensely to proactive participation of key players in the public and private sectors, the interpretation of knowledge produced by academia and professional organizations that aids in better understanding for ease of planning and implementation becomes a challenging and rigorous task. The aim of this paper is to present a conceptual framework that simplifies the interpretation of ‘knowledge creation’ and ‘knowledge dissemination’ connecting the Sendai priority one focus and requisite actions for disaster risk reduction at local, national, global and regional levels. The intended outcome is to better enhance understanding using ‘knowledge’ as a lens for key players and stakeholders involved in disaster risk reduction activities. This is achieved through the review of the role of knowledge and knowledge management literature for understanding disaster risks and utilizes an exploratory approach to further create a theoretical linkage with the focus of the Sendai Framework. The paper suggests that appropriate and continuous interpretation of knowledge created and disseminated has the propensity to stimulate and assist in achieving improved disaster risk reduction outcomes and judicious harnessing of resources required for achieving such tasks. The limitation of this paper is that it utilizes a knowledge lens to achieve its aim while acknowledging that other lenses can be used to provide better understanding and clarity of the subject matter. [ABSTRACT FROM AUTHOR]