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Abstract: This paper presents a method to predict the through-thickness moisture content distribution and associated induced deformations of paper and cardboard sheets as they are subjected to relative humidity changes. The transient moisture diffusion problem is solved using a “natural” analytic approach that has previously been applied for solving transient heat conduction in multi-layer solids. The deformation behaviour of the sheet during the moisture diffusion process is predicted using a semi-analytical approach based on a Rayleigh–Ritz minimization of the total potential energy. Geometrically nonlinear effects are taken into account. Curvatures of the originally flat sheet are predicted as a function of time, as are the shapes of the sheet for steady-state condition. As multiple solutions exist, stability is studied. The developed model was used to study the deformation behaviour of one paper and two cardboard sheets. Comparisons with finite-element results demonstrate that the developed model provides accurate results. The displacements obtained for steady-state conditions are within +6%. Comparisons with previous steady-state analyses reveal important differences in the shape of one cardboard sheet. This suggests that the moisture diffusion process may influence the configuration assumed by the sheet at steady-state equilibrium. Hence, it may be necessary to take the moisture diffusion into account in the analysis to accurately predict the hygro-mechanical behaviour of paper or cardboard sheets. [Copyright &y& Elsevier]

Linear transverse flux permanent magnet machines (LTFPMs) are categorized as high force density topologies, which are suitable candidates for direct drive and low-speed applications. This paper introduces a novel LTFPM topology, which also proposes advantages of the flux-switching machines. This proposed linear transverse flux switching PM machine (LTFSPM) has two long passive translators located at the armature's top and bottom sides. The topology offers a high value of force density, and also, it is a cost-effective topology due to its double-sided passive translator. Furthermore, the PMs are fully utilized in the magnetic circuit, the end winding length is negligible, and the iron cores can be laminated easily. In this paper, the operation principle of the topology is explained and its magnetic circuit is discussed. To reduce the computational time of optimization procedure, a double-layer method is adopted, which provides high robustness, low computational time, and high precision. Results of the finite element method indicate that the proposed machine can be considered a potential candidate for linear motion applications especially direct drive wave energy conversion systems, which require high force density values. [ABSTRACT FROM AUTHOR]

This paper presents an efficient parallel computing strategy to solve large-scale structural vibration problems. The proposed approach utilises a novel direct method that operates using simplex-shaped space-time finite elements and allows for the direct decoupling of variables during the assembly of global matrices. The method uses consistent stiffness, inertia and damping matrices and deals with non-symmetric matrices. One significant advantage of this approach is that the computational cost remains unaffected by the bandwidth of the matrix in the traditional sense because only non-zero coefficients are retained. The speed of computations demonstrates a noticeable increase as the number of nodes and the problem's dimensionality grow. To demonstrate the effectiveness of the parallel space-time approach, a comparison with a sequentially executed code was conducted. The results indicate that the proposed method enables calculations at least 20 times faster than those achieved using the classical finite element method. Furthermore, the parallelisation algorithm was successfully implemented to solve a dynamics problem involving a large-scale, three-dimensional railway structure subjected to a moving load. Remarkably, the problem was solved in a reasonable amount of time using a relatively low-cost personal computer. • Strategy allows efficient parallel computing for large scale structural problems. • Direct method uses simplex-shaped space-time finite elements. • Variables are decoupled while assembling global matrices. • Computational cost is independent of the bandwidth. • Simulations of travelling load problems exhibit twenty times faster computations. [ABSTRACT FROM AUTHOR]

This paper proposes a robust finite element Kalman filter for the state estimation of flexible space tether systems, which are critical for space exploration and satellite missions. Due to the limited access to placing sensors along the flexible tether to measure them directly, the measurement of the state of these systems is challenging. To address this, a fully expandable, scalable, and robust approach is developed that fuses position/velocity sensors at tether ends, distributed fiber optic strain measurement along the tether, and a position/velocity estimation by a finite element-based Kalman filter to estimate the state of the tether system. The proposed estimator is mathematically proven to be observable, stable, and robust. The effectiveness of the estimator is demonstrated through numerical simulations of a space tether system in orbit, and the method can be extended to any flexible body system. The results of the simulations show that the proposed approach can accurately estimate the state of the tether system, even in the presence of disturbances and noise. • Expandable, scalable FE-Kalman state estimator for flexible space tether systems. • Data fusion with tether end position/velocity, distributed fiber optic strain measure, and estimated internal position/velocity. • Mathematically proven observability, stability, and robustness to noise of the estimator. [ABSTRACT FROM AUTHOR]

This paper is devoted to the numerical analysis of a control constrained distributed optimal control problem subject to a time fractional diffusion equation with non-smooth initial data. The solutions of state and co-state are decomposed into singular and regular parts, and some growth estimates are obtained for the singular parts. By following the variational discretization concept, a full discretization is applied to the corresponding state and co-state equations by using linear conforming finite element method in space and piecewise constant discontinuous Galerkin method in time. Error estimates are derived by employing the growth estimates. In particular, graded temporal grids are adopted to obtain the first-order temporal accuracy. Finally, numerical experiments are performed to verify the theoretical results. [ABSTRACT FROM AUTHOR]

In order to understand the mechanism of lining failure caused by creep, it is significant to evaluate the three creep stages of lining materials. In this paper, the three stages creep curves of 3 MPa, 3.25 MPa and 3.5 MPa for high alumina bricks at 1350 °C were obtained by high temperature creep testing equipment. Then the K-R model, the Sinh model and the Liu-Murakami model combined with the Garofalo formula are used to fit the measured creep curves. The results show that all the three models are suitable for the description of the creep behavior and the creep life prediction of high alumina bricks, and the Sinh-Garofalo model has the best fitting effect. Therefore, the Sinh-Garofalo model is selected for finite element modeling. The reliability of the model is verified by comparing the simulated and analytical values. Finally, by comparing the model with/without considering the creep damage, it is found that the creep damage model can be used to characterize the creep damage evolution process and predict the life of structures, which can be further used in the failure study of furnace lining. [ABSTRACT FROM AUTHOR]

This paper presents a detailed treatment of the formulation for buckling and free vibration analysis of Bi-Directional Functionally Graded (BDFG) Thin-Walled non-prismatic beams of generic open/closed cross section. The theory developed is limited to small strains, moderate deflections and small rotations. It is based on the assumption that the shear strain on the mid-surface contour of the cross section of the member is neglected. Using the membrane theory of shells rigorous expressions for strains are obtained by which the effect of nonlinear tapering is considered. The material properties are assumed to be graded both in the longitudinal and depth-wise directions of the plate segment of the thin-walled beams. The governing equations are developed defining the displacements with reference to any arbitrary point (say geometric centre) and get away with the usual shear centre and centroid. For computer solutions for classical buckling and vibration analyses, the Finite Element Method is used. Simpson's rule of numerical integration is adopted for the computation of axial, coupled and bending rigidities as well as inertial properties of the plate segment and the Gaussian Quadrature of numerical integration is used for the computation of flexural stiffness, geometric stiffness and mass matrices of an element over the length of the beam. Critical buckling loads and the natural frequencies and their corresponding buckled and mode shapes for various examples are obtained by solving as an eigen-value problem and compared with the published results in the companion paper. • Using Membrane theory of shells, rigorous expressions for strains have been developed. • The governing equations for BDFG thin-walled beams are arrived at defining displacements with respect to any arbitrary point. • Different material and geometric variations are considered in this paper. • Property constants are determined using Simpson's rule and elements of Stiffness, Mass matrix using Gaussian quadrature. • Static, Stability and Free vibration of BDFG tapered beam of generic open/closed sections can be investigated. [ABSTRACT FROM AUTHOR]

In this paper we present an investigation of the impact of cold-formed steel channel section columns when subjected to an axial impact by a rigid impactor. The work involves both the numerical simulations and experimental tests. The former was done by using nonlinear finite element analysis method and the latter was done by using drop hammer tests. In the present finite element analysis, material nonlinearity, strain rate effect, initial geometric imperfection, and interactions between the impactor and column are considered. It is shown that the impact deformation of the channel-section column under the axial impact of rigid impactor can be characterized initially by its axially compressive deformation, followed by the localized bending deformation in the region where the geometric imperfection is large. The validation of the numerical results using the drop hammer test results demonstrates the appropriateness of the numerical model developed in the paper. • It presents original experimental data of axial impact tests of CFS channel section columns. • FE analysis is provided to simulate axial impact tests of CFS channel section columns under different impact velocities. • Initial geometric imperfection of CFS columns and uses strain rate-dependent elstoplastic stress-strain equation. • The results show that impact velocity significantly affects the final residual deformation of columns. [ABSTRACT FROM AUTHOR]

In this paper, we propose a finite element method for solving viscoelastic hyperbolic integrodifferential equations with L 1 kernel, involving a nonlocal and nonlinear damped coefficient. Firstly, we discuss and deduce that the L 1 kernel is of positive type in two cases. Subsequently, based on the continuous Galerkin technique and the energy argument, we prove the global existence and uniqueness of the discrete solution. Finally, using the basic properties of the positive-type kernel, we derive the error estimates of the finite element solutions. [ABSTRACT FROM AUTHOR]

This paper presents the application of a thick-shell nonlinear finite element analysis procedure to estimate the punching shear resisting performance of reinforced concrete slab-column connections under variable connection shear stress conditions. In the analyses performed, varied connection shear stress conditions stem from slabs being supported by columns with different cross-section aspect ratios, being subjected to different distributions of gravity loading, being constructed with different planar reinforcement ratios in orthogonal directions, as well as the application of unbalanced bending moments. Forty-eight isolated slab-column connection specimens presented in the literature were modelled and analyzed using a thick-shell finite analysis procedure. All numerical results were developed using a predefined set of material models and analysis parameters, a consistent meshing procedure, and are shown to provide meaningful agreement with experimental data without the need for case-specific model calibration or the adoption of specialised failure criteria. The results show that thick-shell modelling methods can be suitable for estimating the punching shear response of slabs subjected to non-uniform shear stress development in connection regions, and can provide similar levels of precision to that obtained for the analysis of idealised slab-column connections typically used for design procedure and model development. • Low-cost shell FEA for punching shear assessment of reinforced concrete flat plates. • Analysis of 45 non-idealised connection specimens representative of real-world construction. • Good agreement between FEA simulations and reported results without model calibration. • Result accuracy comparable to that obtained for more typical idealised connection specimens. [ABSTRACT FROM AUTHOR]

This paper studied the axial compression behavior of the steel tube reinforced concrete (STRC) column, which consisted of inner CFST and outer RC components. Ten specimens, including seven STRC columns, two RC columns, and one CFST column were tested. The test parameters included the CFST area ratio (inner CFST to the whole section), longitudinal rebar ratio and stirrup space. The test results showed that the compressive behavior of STRC column with a CFST area ratio of 0.04 was close to that of the RC column, and the compressive behavior of the STRC column with a CFST area ratio of 0.13 was between that of the RC column and CFST column. The finite element (FE) models were developed and verified by test results to investigate the effects of longitudinal rebar ratio and stirrup space on the axial compression behavior of STRC column with various CFST area ratios. The load distribution between inner CFST and outer RC components was analyzed. The FE results showed that the effects of the longitudinal rebar ratio on the ultimate load of STRC column were related to the CFST area ratio. The accuracy and applicability of the five methods suggested by codes for predicting the ultimate load of STRC column were discussed based on the test and FE results. • The compression test of steel tube reinforced concrete (STRC) column with low CFST area ratio was firstly carried out. • The influences of both CFST area ratio and longitudinal rebar ratio on ultimate strength of STRC column were discussed. • The refined finite element model of STRC column for parameter analysis is established. • The five methods of codes for ultimate strength of STRC column was calculated and discussed. [ABSTRACT FROM AUTHOR]

Highlights • Beam finite element with eccentric, variable neutral axis. • Non-linear materials and material softening considered. • Computationally efficient finite element formulation. • Case studies considering large deflections and material nonlinearity considered. • Applicable to composite beams, bridge decks and other similar structures. Abstract This paper presents a beam finite element and analysis methodology for structures with neutral axes (NA) that are eccentric to the positions about which they are modelled, and that change position during the process of an analysis. This NA shift occurs due to non-linear material behaviour (softening, cracking, etc.). The proposed formulation is based upon a modified corotational approach. It has been developed specifically for structures subjected to severe fires, although it is also applicable to the non-linear analysis of structures such as wind towers and bridge decks where the position of the neutral axis in a beam section changes due to material nonlinearity. The analysis formulation results in lower computational effort relative to contemporary analysis methods employing shell or volume elements, while providing comparable results. Four case studies that include material nonlinearity, large deflections and geometric nonlinearity are included to validate the proposed formulation, and results are compared to shell element models analysed using Abaqus. The contributions of this paper are: (a) the application of standard Euler beam theory in a novel manner to allow for adjusted position of neutral axes in beams, (b) the presentation of simple case studies that can be used for validating finite element methods, but which incorporate material, geometric and cross-sectional non-linearity, and (c) illustrating the influence of cross-sectional discontinuity and how it may influence results when using beam elements. [ABSTRACT FROM AUTHOR]

Abstract Increasing awareness of environmental concerns is leading a drive towards more sustainable structural materials for the built environment. Natural fibres such as flax and jute have increasingly been considered for fibre-resin composites, with a major motivation for their implementation being their notable sustainability attributes. This paper is part of an ongoing effort by the author to demonstrate the structural properties of primary structural elements and members fabricated from natural fibre composites of flax and jute. Previously the structural properties of flat plates, plain channel sections and channel sections with complex stiffeners were investigated under pure compression. This paper presents investigations of channel sections with complex stiffeners under pure bending. A series of sixteen channels with varying geometries, complex stiffener arrangements and composite thicknesses were tested in pure flexure. Material tests indicated that the mean tensile elastic stiffness and strength values were 6386 MPa and 55.1 MPa for flax, and 6941 MPa and 62.1 MPa for jute. The experimental results indicated that flexural failure of the channel sections was governed by tensile fracturing. The ultimate moment capacities varied from 1.043 to 1.501 kNm for four-layered composites, and 2.184 to 2.511 kNm for six-layered composites. The analytical models predicted the experimental ultimate moment capacities well, with a mean and coefficient of variation of the test to predicted ratio of 0.97 and 0.06, respectively. Finite element models used progressive damage analysis via stress-based damage initiation models and damage evolution laws, to replicate the tension fracture failure mode of the channels. The numerical models predicted the experimental ultimate moment capacities well, with a mean and coefficient of variation of the test to predicted ratio of 0.99 and 0.06, respectively. [ABSTRACT FROM AUTHOR]

Abstract This paper presents in a unified and comparative manner, the formulation of two triangular plate bending composite elements, i.e. DKMT and MITC3 which are published in 1993 and 2004. Both elements have 3 nodes and 5 dof per node (three displacements and two rotations), taking into account transverse shear effects. There are valid for thin to thick composite plates, and give good results in classical benchmark and patch tests. The numerical results using DKMT element show the optimal and uniform convergence for thin and thick plates with an advantage for DKMT compare to MITC3 due to semi quadratic interpolation for the rotation variables The present paper contains new convergence analysis based on the s -norm tests for sandwich plates considering uniform and distorted meshes, and for symmetric and non symmetric composite plates with 3 and 9 layers. As the novelty and main contribution of this article, we propose the shear projection method in the element formulations to show the asymptotic equivalence of DKMT and the MITC3 for thick to thin composite plates. [ABSTRACT FROM AUTHOR]

Abstract A common form of coastal protection in New South Wales, Australia, is the rubble mound breakwater. This consists of quarried rock or unreinforced concrete armour units. However, increased impact forces on these structures due to greater storm surge levels that are predicted by global warming models, suggest that they will require strengthening. Traditionally steel bar reinforcement is used to strengthen concrete; however, as steel is particularly susceptible to corrosion in aggressive coastal environments, it is not a robust solution. This paper reports on the potential of using macro-synthetic fibre reinforcement in reinforcing of breakwater armour units, in lieu of traditional steel reinforcing bars. To this end, a programme to ascertain the tensile capacity of 0.6 percent and 1.0 percent by volume of concrete reinforced with macro-synthetic fibres was implemented. The behaviour of this synthetic fibre reinforced concrete in Dolos type breakwater armour units was then examined using the finite element analysis software ATENA. The results of the numerical analysis indicate that the addition of synthetic fibres at these volume percentages into concrete armour units improves the post peak response under impact loading by a factor of two to three, compared with unreinforced units. Furthermore, the addition of fibres significantly reduced the maximum crack width for the same number of impact loadings and allows the units to withstand larger crack widths before failure. Highlights • This paper assesses the effectiveness of Dolosse concrete armour units reinforced with 0.6 percent and 1.0 percent of macro-synthetic fibres. • An experimental programme was developed to investigate the post crack capacity of the synthetic FRC. • The experimental results were used to simulate the properties of synthetic FRC in Dolosse breakwater armour units. • The addition of fibres significantly improves the breakwater armour unit's capacity to withstand higher and more numerous impact loads. [ABSTRACT FROM AUTHOR]

This paper presents a methodology for explicit modeling of the time-dependent behavior or creep of structural steel in the Abaqus finite element (FE) models under transient temperature conditions representative of building fires. In this methodology, available creep models based on conventional creep tests under constant or steady-state temperature conditions were used to predict the time-dependent or creep behavior of steel under variable or transient-state temperature conditions. Specifically, user-defined CREEP subroutines were created in Abaqus to define time-dependent or viscoplastic deformation of structural steel under changing temperatures. To demonstrate the robustness of the proposed methodology, the time-dependent behavior of structural steel at elevated temperatures was modeled under three distinct conditions. These were: steady-state temperature conditions, stepwise steady-state temperature conditions, and transient-state temperature conditions. This paper further presents and discusses the application of the methodology in studying the creep behavior of a shear tab connection assembly under the transient temperature conditions of a fire. Through this application, the importance of explicit consideration of creep in predicting the response of connection assemblies at different stages in the evolution of a structural-fire is also emphasized. [ABSTRACT FROM AUTHOR]

This paper presents a new nanoforce sensor based on a suspended carbon nanotube gate field-effect transistor. To do so, a numerical investigation of Suspended Gate Silicon-on-Insulator MOSFET (SG-SOIMOSFET) is carried out using ATLAS 2D simulator. Based on the relationship between the nanotube’s deflection and the applied force, a comprehensive study of the proposed nanoforce sensor behavior is performed. Moreover, we describe the evolution of the drain current characteristics as a function of the applied force while examining the influence of capacity variation of the insulating gate on the drain current in the saturation region. It is found that the sensor has a good sensitivity of 230.68 ln(A)/pN. Our second contribution in this paper is to develop a model based on artificial neural networks (ANNs). We successfully integrate our neural model of nanoforce sensor as a new component in the ORCAD-PSPICE electric simulator library; this component must accurately express the behavior of the sensor. A second model based on neural networks, which deals with correction and linearization of the sensor output signal, is designed and implemented into the same simulator. The proposed device can be considered as a potential alternative for CMOS-based nanoforce sensing. [ABSTRACT FROM AUTHOR]

This paper provides means for obtaining the first three significant vibration modes for rectangular plates based on mass participation ratios. A non-dimensional frequency parameter is presented which results into the vibration frequency of rectangular plates at each of these three significant modes. Various aspect ratios and four combinations of boundary conditions at the plate edges are studied. A correlation between the nonlinear load-deformation behavior of the plate and its vibrational behavior is also presented accordingly. It is demonstrated that the vibration frequency of the studied rectangular plates increases significantly upon increasing the applied lateral pressure if the large deformation effects are considered in the analysis. The easy-to-follow method of frequency calculation presented in this paper is useful for assessing the dynamic characteristics of rectangular plates with or without lateral pressure that are subject to vibration. [ABSTRACT FROM AUTHOR]

In this paper, we are interested in the displacement of two incompressible phases in a Darcy–Brinkman flow in a porous media. The equations are obtained by the conservation of the mass and by considering the Brinkman regularization velocity of each phase. This model is treated in its general form with the whole nonlinear terms. This paper deals with construction and convergence analysis of a combined finite volume–nonconforming finite element scheme together with a phase-by-phase upstream according to the total velocity. [ABSTRACT FROM AUTHOR]

• Design and validation of a sealing and closing system for a Sample Return mission. • Testing in relevant environment of a space mechanism for sample return missions. • Development of a scalable closing mechanism able to release a high pushing force. The present paper addresses the development of a closing and sealing system for a container which shall safely bring 100 g of regolith from the surface of Phobos, one of the moons of Mars. Based on a set of requirements defined by the ESA (European Space Agency), a design of the closing and sealing system was made and FEA (Finite Element Analysis) was employed to validate the design. The closing and sealing mechanism along with the Vault (container to be sealed) proved the capability to overcome the Robotic Arm misalignments, to ensure the Vault closing and to maintain the leak tightness (maximum admissible leak rate of 10−4 mbar*l/s Helium) during the trip back to Earth. All these features were validated following an extensive test campaign implying mechanical loads, shocks, thermal vacuum cycling, dust contamination, impact tests and several functional verifications. The mechanism demonstrated the targeted maturity level (TRL 5) and it can be further developed in order to be qualified for a specific mission/application. [ABSTRACT FROM AUTHOR]

In this paper, the finite element method is utilized to evaluate the behavior of the armchair phosphorene nanotubes under the compressive loading. The energy equations of the molecular and structural mechanics are used to obtain the elemental properties. The critical compressive forces of various armchair phosphorene nanotubes are computed with clamped-clamped and clamped-free boundary conditions. Results show that the stability of armchair phosphorene nanotubes increases with increasing nanotube aspect ratio, particularly under clamped-clamped boundary conditions. Finally, the buckling mode shapes of armchair phosphorene nanotubes under different boundary conditions are compared. Our work offers valuable insights into how these nanotubes respond to mechanical stress, helps determine elemental properties, and investigates the effects of nanotube geometry and different boundary conditions on their stability. This knowledge has broad applications in fields like nanotechnology, materials science, and nanomechanics, advancing the understanding of nanoscale materials and their potential for various practical uses. The finite element method is utilized to evaluate the behavior of the armchair phosphorene nanotubes under the compressive loading. [Display omitted] • FE method is utilized to evaluate the behavior of the armchair PNTs under the compressive loading. • The elemental properties are obtained by the energy equations of the molecular and structural mechanics. • The buckling forces of the armchair PNTs with different radii and lengths are computed. • The stability of armchair PNTs increases by increasing the nanotube aspect ratio. • The clamped-clamped nanotubes are more stable than clamped-free ones. [ABSTRACT FROM AUTHOR]

Metamaterial structures that exhibit negative stiffness (MSNS) behavior have shown the potential to be used as energy dissipation systems in different applications. Negative stiffness honeycomb structures consist of multiple pre-buckled beams that snapping through from one pre-buckled mode to another buckled mode, when subjected to transverse loads, displaying negative stiffness, and dissipating a significant portion of the input energy. This paper presents finite element models (FEMs) developed to investigate the performance of negative stiffness pre-buckled beams and honeycombs. The FEMs were validated using experimental results of single pre-buckled beams and honeycomb structures. The experimental testing of the pre-buckled beams was presented in the current study while the results of the honeycomb were available in the literature. The FEMs have the ability to capture the transition of the elements from one mode of buckling to another mode as well as the force thresholds, energy dissipation values, and residual displacements. The FEMs were extended to investigate the effect of different parameters such as boundary condition, apex height-to-beam thickness ratio, and constraining the second mode of buckling on the behavior of negative stiffness honeycombs. • Metamaterial structures that exhibit negative stiffness (MSNS) have potential for use in energy dissipation systems. • Finite element models (FEMs) are presented to study the performance of MSNS beams and honeycombs. • FEMs are validated using experimental results from single pre-buckled beams and honeycomb structures. • FEMs can accurately predict transitions between different modes of buckling, force thresholds, and energy dissipation. [ABSTRACT FROM AUTHOR]

• Micro-piling implemented as minimally disruptive trackbed stabilisation technique at a soft subgrade rail site. • Computer vision-based monitoring system measures track deflection under train passage to quantify trackbed quality. • Stabilisation improved trackbed quality by up to 30% and 50% improvement is achievable with clean ballast and longer piles. • Finite element analysis identifies triangular pile layout as an optimum configuration for cost vs improvement %. Excessive deflection of a rail in response to axle loading can lead to discomfort for passengers and increased wear of both railway structures and trains. These oscillations are often caused by poor trackbed stiffness which may be due to either soft subgrade and/or contaminated ballast. A variety of trackbed stabilisation (TBS) techniques are available to remediate soft subgrades and increase the safety of tracks within the railway network. Traditional TBS methods require track removal, which is expensive, disruptive and often inefficient maintenance works. Micro-piling, using screw piles installed between sleepers, is an innovative low disruption TBS technique. This paper investigates the performance of a soft subgrade and contaminated ballast section of rail line in the UK, before and after screw pile TBS. Pre and post remediation, a computer vision-based system was used to measure rail vertical deflections during train passages and then analysed to quantify the trackbed stiffness. Additionally, 3D finite element models are created and validated by the site measurements. The finite element models are used to simulate a range of different scenarios exploring how changes to the TBS piling layout and/or further works, such as ballast improvement could add further improvements or design efficiencies. Site measurements show TBS reduced rail deflection by 20–30%, indicating that micro-piling is an effective technique for soft subgrades. The finite element analysis revealed the efficiency of micro-piling is highly dependent on the conditions of ballast, strength of the ground at the pile toe, and the pile arrangement. When the aforementioned are optimised the rail deflection could be reduced to approximately 50% of the pre TBS condition. [ABSTRACT FROM AUTHOR]

This paper made pilot studies on behaviours of concrete-filled stub square stainless-steel tubes (CFSSSTs) subjected to low-temperature compression. Firstly, 16 CFSSSTs were tested under low-temperature axial compression. This testing program studied the effects of testing temperature (T) and SS-tube wall thickness (t). The tests showed that local buckling, corner-region splitting fracture, and concrete crushing occurred to CFSSSTs. The compressive load-shortening curves behaved a four-stage manner, which behaved differently from those hollow stainless-steel tubes (HSSTs). Compared with the common concrete-filled steel tube columns, the CFSSSTs exhibit a higher ductility. Studies showed that reducing T improved the compression capacity (P u) but compromised the ductility of CFSSSTs; increasing the t of HSSTs improved the compression behaviour of CFSSSTs; filling concrete to the HSSSTs significantly improved the compression behaviour of CFSSSTs. This study also developed 3D finite element models (FEM) for the CFSSSTs using the low-temperature mechanical properties of both HSSTs and concrete, which accurately predicted compression behaviours of CFSSSTs at low temperatures. Moreover, the prediction equations in different codes were also adopted to predict the low-temperature P u of CFSSSTs. Validations showed that these code equations provided about 15% underestimations on P u , and they were recommended to predict P u of CFSSSTs at low temperatures. • Arctic low temperatures improve compressive behaviours of concrete-filled square stainless-steel tubes (CFSSSTs). • Low temperatures have limited effects on failure modes of CFSSSTs. • Low temperatures improve compression capacity, but reduce the ductility of CFSSSTs. • Developed FEM predict well low-temperature compressive behaviours of CFSSSTs. [ABSTRACT FROM AUTHOR]

For estimation of the durability of recycled aggregate concrete (RAC) in chloride-rich environment, it is valuable to investigate the chloride diffusivity in RAC. Because RAC is highly heterogenous, an ideal five-phase model was designated as the representative research object of RAC in this paper. To investigate the effect of micro-scale randomness on the meso -scale chloride diffusivity in RAC, this paper developed a multiscale digital-image driven stochastic method, in which the digital-image covariance kernel was used in the Karhunen-Loeve expansion to generate basis functions for the model. The proposed method was at the first time used to analyze chloride ion diffusion in RAC. Through a couple of numerical experiments, it is indicated that the effects of aggregate shape, aggregate size and the thickness of interfacial transition zones (ITZs) are considerable on the coefficient of variation of chloride diffusivity in RAC. It is also found that the digital image kernel is more sensitive about noise than other standard covariance kernels. [ABSTRACT FROM AUTHOR]

Helmholtz resonator is one of the most basic acoustic models in acoustic theoretical research and engineering applications. It is simple and effective to directly apply the theoretical formula for its resonant frequency calculation, but sometimes the calculation error is too large or even wrong. In this paper, the characteristics of Helmholtz resonators are studied based on the finite element numerical analysis. The influence of structural parameters and boundary conditions of the Helmholtz resonator on the resonant frequency is given, several related problems of the theoretical formula are supplemented and the relevant conclusions are obtained. The explanations employed in this paper could be used as a supplement to the theoretical formula for theoretical study and engineering applications of Helmholtz resonators. [ABSTRACT FROM AUTHOR]

A numerical investigation on cold-formed high strength steel (HSS) tubular beams is presented in this paper. The nominal 0.2% proof stresses of the HSS sections ranged from 700 MPa to 1100 MPa. In the complementary study [1], experimental investigation on the beam specimens have been performed. In the present study, numerical modelling methodology for beams was first validated and parametric study on the cold-formed HSS tubular beams was conducted. A total of 423 numerical data was obtained to investigate the structural performance of HSS tubular beams. The experimental and numerical results were then compared with the codified design guidelines from ANSI/AISC 360-10 [2], EN 1993-1-1 [3], AS 4100 [4] and AISI S100 [5] in addition to the predictions from Direct Strength Method (DSM) for square hollow sections (SHS), rectangular hollow sections (RHS) and circular hollow sections (CHS). The codified slenderness limits for sections subjected to bending were examined. Improvements on the design guidelines are proposed in this paper. [ABSTRACT FROM AUTHOR]

This paper presents the results of a combined experimental and numerical investigation on the mechanical behaviour of annealed glass–Glass Fibre Reinforced Polymer (GFRP) hybrid beams. The experimental results showed that an adhesively-bonded GFRP interlayer significantly improved the strength and ductility of annealed glass beams. The paper also presents the post-breakage behaviour and the response of damaged beams in unloading. The paper numerically investigates the degree to which the strength and stiffness of the hybrid beams can be modelled by using finite element (FE) analyses. The novelty of work also includes numerical modelling and validating the through-thickness stress profiles in the hybrid beams. [ABSTRACT FROM AUTHOR]

Surface roughening is essential for the design of new nanostructures. In this paper, a continuum model based on phase field theory is developed to study the surface roughening in heteroepitaxial structures. A long-range order parameter is introduced to represent a diffusional free surface profile. By minimizing the system total free energy under constraints, the coupled field equations of quasi-static mechanical equilibrium and diffusion-controlled surface evolution are obtained. In contrast to the existing phase field models of free surface which are mostly based on the analytical Green’s function, the Galerkin finite element formulation is derived in this paper to solve the weak form of the coupled field equations. The advantage is that it is very convenient to deal with the elastic inhomogeneities and complex boundary conditions without additional complications. The proposed model is applied to study the nonlinear surface morphology evolution of heteroepitaxial thin films. The simulation shows that the heteroepitaxial film with an initial random fluctuation develops to form islands and coarsens during annealing. The kinetics of coarsening and the calculated average wavelength are consistent with the existing experimental results. It also shows that the initial island array formed during annealing consists of islands with similar size, shape and spacing. The influences of film thickness and misfit strain on the formation of initial island array are studied. [ABSTRACT FROM AUTHOR]

This paper concerns the short-term behaviour of innovative steel-timber composite (STC) floors comprising of cross-laminated timber panels connected to steel girders by various mechanical fasteners and/or glue. The results of four-point bending tests performed on full-scale STC beams are reported and the structural behaviour (the load-deflection response, short-term stiffness, peak load capacity, and failure modes) of the proposed STC system is studied. In addition, extensive non-linear 1D and 2D finite element (FE) analyses of STC beams are carried out and the numerical results are verified against the test results. It is shown that 1D and 2D FE models are adequate in capturing the structural response of the STC beams. Using the FE and experimental results, the composite efficiency of STC beams that can significantly influence their structural behaviour beams is determined and reported in the paper. [ABSTRACT FROM AUTHOR]

[Display omitted] This paper is devoted to the investigation of the density sorting of grains using water jigging. Experiments achieved in a laboratory scale water jig for two initial binary bed configurations are studied and compared to numerical results. The vertical composition of the deposit is estimated after different number of water pulses to represent the sorting evolution in time. Simulations are based on a multiscale model in which the fluid is solved at a larger scale than the grain diameter using the finite element method, while the grains are considered as rigid bodies and solved using the nonsmooth contact dynamics. Key parameters are numerically varied and observed to determine the sensitivity of the process. • Collective phenomena increase sorting rate in binary mixtures. • Density difference between the materials influences the sorting rate. • Water jigging depends on the friction between densest grains and walls. • Numerically unresolved fluid slip drives the sorting dynamics. [ABSTRACT FROM AUTHOR]

This paper presents an experimental and computational study on the behaviour of pre-tensioned thin solar sails. Firstly, a set of experimental tests of thin rectangular sheets made of Kapton ® subjected to uniaxial tension were conducted to characterize the mechanical properties of the membrane. Then, tri-dimensional digital image correlation technique was used to capture the evolution of the wrinkling (shape and amplitude) in pre-tensioned specimens, a phenomenon that often affects the serviceability of solar sails. The influence of membrane thickness and specimen dimensions on the wrinkling behaviour were also studied. Next, nonlinear finite element models were used to simulate the membranes and to study the onset and growth of wrinkles in solar sails. First, by pre-tensioning the membrane with truss cables and using combinations of the eigenmodes extracted from buckling analysis as the membrane initial geometrical imperfections, nonlinear analyses were performed. The computational methodology was verified by comparing the experimental results of membrane specimens with those obtained from finite element analysis. Because the number of truss cables that pre-tension the solar sail plays a key role in their behaviour, two distinct configurations were considered: (i) five points connected sail and (ii) multiple points connected sail. Sensitivity studies were performed, including the influence of (i) membrane size and (ii) pre-tensioning magnitude on the solar sail wrinkling. Larger sails exhibit higher wrinkle dispersion and amplitude. Higher pre-tensioning induces more wrinkles, higher amplitudes and lower wavelengths. The solar sail configuration with multiple connected points connected presents less wrinkles with lower amplitude, and it is preferable to the configuration with five connected points. Finally, it was revealed that the wrinkling maximum amplitude varied approximately in a power law with the pre-tensioning level. [Display omitted] • This paper investigates the structural behaviour of pre-tensioned thin solar sails. • Experimental results on the mechanical properties and wrinkling of Kapton ® membranes were obtained. • Nonlinear finite element results were verified by comparison with test results. • Solar sail with multiple connected points are less sensitive to wrinkling than the one with five connected points. • The wrinkling amplitude varied approximately in a power law with the pre-tensioning level. [ABSTRACT FROM AUTHOR]

In this paper, the stress-strain behavior of an elastic-plastic ellipsoidal inclusion embedded in an infinite elastic matrix is studied. The parent elastic material is considered to be subjected to monotonically increasing far-field stresses. Stress-strain behaviors of the inclusion are first studied using the commercial finite element package ABAQUS. Then a semi-analytical method is developed using suitable extensions of the formulas used in Eshelby's inclusion problem (1957). An excellent agreement in stress-strain behavior is found between the finite element results and the semi-analytical method. The major contribution of this paper is, therefore, the development of the semi-analytical method that has several advantages over the finite element solutions. The semi-analytical method is quick and accurate. Additionally, when the inclusion geometry is very thin, the semi-analytical method remains viable while the finite element method would require infeasibly finer mesh refinement. [ABSTRACT FROM AUTHOR]

This paper investigates the mechanical behaviour of lap steel-timber composite connections using a 3-D continuum-based finite element (FE) model. In the FE models developed, the non-linear behaviour and failure of the timber is captured by a stress-based failure criterion formulated in the framework of continuum-damage mechanics. Yielding of the steel plates and fasteners ( i.e. coach screws and bolts) is captured by an elastic-hardening plastic constitutive law. These FE models are validated by experimental (push-out) tests conducted on laminated veneer lumber (LVL)-steel and cross-laminated timber (CLT)-steel composite lap connections. It is shown that the FE models developed in the paper can replicate adequately the load-slip response and failure mode of the hybrid steel-timber composite connections tested. The validated FE model is used to undertake a parametric study that elucidates the influence of the yield strength and the length of the fasteners and the post-tensioning force in the bolts on the stiffness, load carrying capacity and load-slip behaviour of hybrid steel-timber composite connections. [ABSTRACT FROM AUTHOR]

In this paper, supermode characteristics of a dual-core fiber and a four-core fiber are analyzed by a simple couple-mode theory. The effective refractive index and corresponding relative error of each supermode are investigated in detail with different gapsize, relative refractive index and core radius using numerical method and finite element method. Both adjacent coupling and non-adjacent coupling are taken into consideration when keeping single mode condition of each core. The magnitude of relative error can achieve 10 −5 and 10 −4 for a dual-core structure and a four-core structure, respectively. The obtained results clearly show the validation of numerical method compared with finite element method. One is going to benefit from the succinct equation expressions in this paper when designing and analyzing supermode supporting fiber structure. [ABSTRACT FROM AUTHOR]

In this paper, a piecewise shear deformation theory for laminated composite and sandwich plates is presented by integrating the advantages of the layerwise theory and equivalent single layer theory. A C 0 continuous four-noded quadrilateral isoparametric plate element based on this theory is developed for free and forced vibration analysis of laminated composite and sandwich plates in thermal environments. The accuracy and effectiveness of piecewise shear deformation theory and finite element formulation are validated by comparing the numerical results obtained by the present finite element formulation with the analytical and exact results available in literatures as well as the numerical results computed by MSC.Nastran software. It is demonstrated that the piecewise shear deformation theory and finite element formulation are suitable for the vibration analysis of thin and thick laminated composite and sandwich plates. As compared with the layerwise theory, high-order zigzag theory and high-order equivalent single layer theory, the piecewise shear deformation theory is able to produce a sufficiently accurate result at a very low computational cost. The work reported in this paper provides an efficient modeling approach for thermal vibration analysis of laminated composite and sandwich plates in practical engineering. [ABSTRACT FROM AUTHOR]

This paper presents a case study and numerical investigation of two unstable unsaturated slopes along the Taipei Maokong Gondola system. One slope collapsed because of torrential rainfall during Typhoon Jangmi in September 2008, and another nearby slope developed excessive deformation under consecutive wetting and drying cycles. Recorded rainfall, measured soil parameters, site geology, and slope geometry were used in coupled hydro-mechanical finite element analyses to investigate the failure and deformation mechanisms of these two slopes. The stress paths of these two slopes were also examined and are discussed in this paper. The numerical results demonstrated that the coupled hydro-mechanical analysis satisfactorily predicted the failure and deformation characteristics of the two unstable slopes. In the collapse case, failure occurred at a shallow depth when the surficial residual soil was saturated. The slope failure was attributed to a decrease in soil shear strength when the matric suction gradually decreased as rainfall progressed. In the excessive deformation case, the numerical results suggested that pore water pressure (PWP) varied at shallow depths under wetting and drying cycles, whereas positive PWP accumulated at the soil–rock interface and induced non-uniform lateral flows parallel to the interface. The accumulated positive PWP at the interface mobilized a considerable plastic deformation in the soil. Examination of the relationships between the slope factor of safety and the corresponding hydrological data (i.e., rainfall and soil PWP) revealed a positive correlation between the slope factor of safety and accumulated rainfall. The factor of safety predicted by the infinite slope equation significantly varied with the input of PWP. This study demonstrated that the infinite slope equation using the PWP measurements obtained from the lower half of the slope could effectively predict the slope factor of safety. [ABSTRACT FROM AUTHOR]

Numerical and analytical modelling approaches are often competing to describe a desired phenomenon. However, there is no reason to look for a single method and complementarities between distinct modelling ways are always profitable. This paper, the first of a set of two consecutive papers published in this volume, provides such a modelling methods reconciliation in the case of transport phenomena acting in transversely isotropic multi-phased materials. Microstructural Finite Element Modelling (FEM) helps supplying the analytical implementation for a better description of interactions between the constituents. As an application example, the case of molecular diffusion within a unidirectional composite medium is investigated without any restriction for considering any other transport mechanism. Based on a rational microstructure description, this study proposes a model able to predict the overall diffusion tensor of the composite and investigates more particularly diffusivity effects of interphase areas and fibre packings. For this purpose, a “ n -phase” Generalized Self-Consistent Scheme (GSCS) coupled with a Morphologically Representative Pattern (MRP) approach has been developed. This first part is focused on the modelling strategy and the concept of “transfer matrices” has been used. This approach is applied in Part II (Joannès and Hervé-Luanco, 2016) to study the influence of fibre packings on the effective behaviour of composite materials made of insulated fibres embedded in a diffusive matrix. [ABSTRACT FROM AUTHOR]

A recent comprehensive investigation into residual stress distributions in pipe and vessel longitudinal seam welds is presented in this paper, covering component wall thickness from 1/4″ (6.35 mm) to 10″ (254 mm), component radius to wall thickness ratio from 2 to 20, and linear welding heat input from low (50 J/mm) to high (6000 J/mm). Through the use of a residual stress decomposition technique, two key parameters that govern through-thickness residual stress distributions in terms of their membrane and bending content have been identified. One is component radius to wall thickness ratio ( r / t ) and the other is a characteristic heat input density ( Q ^ ) having a unit of J/mm 3 . With these two parameters, a unified functional form for estimating through-thickness residual stress profile in seam welded components is proposed in this paper (Part I) for supporting fitness for service assessment for crack-like flaws in weld region. A curved beam bending theory based model is introduced in Part II as a means of analytically describing through-thickness residual stress profile as a function of circumferential position away from the weld region until residual stresses become zero. The effectiveness of this proposed framework for achieving residual stress profile estimation within weld region (Part I) for longitudinal seam welds in pressure vessel and piping components has been confirmed by finite element residual stress analysis results on a large number of component configurations and different welding conditions. [ABSTRACT FROM AUTHOR]

The mechanical response of a wire strand is inherently complex because the helical wires undergo evolving stress and contact conditions as the strand is loaded. Further complications are added to the strand behavior if one or more of the wires break due to strand degradation over time. Although a detailed investigation on strand behavior is critically important for predicting the capacity of a broken strand as well as developing new monitoring approaches for wire break detection, there is little study available in the literature on wire breakage in a stressed strand. This paper provides an extensive investigation on stressing and post-breakage dynamic behavior of a prestressing strand. A finite element model is generally useful to study the global strand response, along with many localized phenomena that have strong influence on its performance, but are difficult to capture either experimentally or through closed-form analytical models. Investigations on certain behaviors, such as wire breaks, however, require a relatively large or even a full-scale model to adequately develop contact and frictional conditions. Moreover, such a sizeable model can account for any deviation points and may avoid edge effects. Consequently, several finite element parameters, such as the load ramp profile and duration, effects of damping and interwire friction, become critical for an accurate and efficient model. This paper first presents the use of a parametrized model to study strand behavior and evaluates the effects of these modeling parameters on strand response; load distribution and redistribution among the wires at the onset of interwire motion are also considered. The model is then used to simulate wire breakage in a prestressing strand, so that various aspects of post-breakage response can be examined. Numerical results show that a linear load ramp or stressing too quickly may lead to an inaccurate axial tension developed in the strand, whereas the inclusion of nominal mass-based damping has been found effective in achieving a quasi-static solution at a reasonable computational cost. In addition, the wire break simulation results indicate that breakage of an outer wire results in greater prestress loss than breakage of the center wire, which might have important implications for non-destructive wire breakage detection. [ABSTRACT FROM AUTHOR]

Wave propagation in soil is dependent on both the stiffness and the material damping of the soil. While some researchers have performed finite element modelling of resonant column tests and wave propagation in soil, most do not describe the methodology in detail and there is little or no verification of the correctness of the model. Viscoelastic model has been used to model wave propagation in soil. However, the determination of the parameters in the viscoelastic model is complicated and the parameters may not be related to the soil properties. This paper presents a simplified viscoelastic model with soil parameters obtainable from advanced geotechnical testing to simulate wave propagation in soil medium taking into account of material damping. The viscoelastic material model was first calibrated by replicating torsional, longitudinal and flexural modes resonant column tests. The relationships between the parameters of the simplified viscoelastic model and their corresponding stiffness and damping properties were investigated. An equation was proposed to correlate the decay constant used in the simplified viscoelastic model and the material damping ratio obtained through the application of the logarithmic decrement method on the modelled resonant column test results. The simplified viscoelastic model was then evaluated by modelling wave propagation in a semi-infinite medium. Results indicated that the viscoelastic model with parameters as proposed in this paper is able to model wave propagation in soils. [ABSTRACT FROM AUTHOR]

The aim of the present paper is to provide an efficient numerical technique to evaluate the linear elastic stress parameters to use in an existing fatigue model. The model allows to assess the tensile fatigue limit of components weakened by defects, cracks, sharp as well as blunt notches with an arbitrary notch opening angle. To apply the fatigue model, both the elastic stress concentration factor of the notch and the notch stress intensity factor of the corresponding sharp notch must be evaluated. Therefore, in principle two different linear elastic stress analyses should be performed. The novel technique proposed in the present paper involves only a single linear elastic stress analysis, consisting of a sharp and coarse finite element model: sharp because the notch tip radius is set to zero, and therefore a sharp V-shaped notch is modelled; coarse because coarse patterns of finite elements can be employed. Approximate values of the elastic stress concentration factor and of the notch stress intensity factor calculated from the sharp and coarse finite element model are compared with very accurate estimations obtained from dedicated analyses. To illustrate the fatigue assessment procedure, experimental notch fatigue limits taken from the literature and characterised by a variety of geometrical configurations are compared with theoretical estimations. [ABSTRACT FROM AUTHOR]

This paper addresses the lack of three-dimensional stress intensity factor solutions for small to large surface cracks located at the weld toe region of welded pipes. A methodology was developed to model and calculate the stress intensity factors and weld toe magnification factors for semi-elliptical surface cracks in a circumferentially welded pipe. Three-dimensional finite element models were developed for a wide range of surface crack geometries. The stress intensity factors for surface cracks in a plain pipe were benchmarked with reported results and showed good agreement to within 2.6%. Stress intensity factors and weld toe magnification factors solutions were determined for weld toe surface cracks located at a circumferentially welded pipe. The weld toe semi-elliptical surface cracks geometries vary from small crack depth-to-thickness ( a / t ) ratios of 0.05 to large crack depth-to-thickness ( a / t ) ratio of 0.5. Three semi-elliptical surface crack shape aspect ratios ( a / c ) were modelled for values of 1.0, 0.5 and 0.25. The stress intensity factor and weld toe magnification factors solutions are reported in this paper for a wide range of semi-elliptical surface crack geometries with crack depth-to-thickness ratios ( a / t ) from 0.05 to 0.5 and crack shape aspect ratios ( a / c ) from 0.25 to 1.0 subject to pipe wall tension and bending loading. The stress intensity factor and weld toe magnification factors solutions are used for fatigue crack growth prediction assessment of weld toe surface cracks propagating in a circumferentially welded pipe. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of cross-section aspect ratio and the effect of load eccentricity on the behavior of RC short columns with large-scale specimens wrapped with external carbon fiber polymers (CFRP) using finite element. Firstly, to study the effect of cross-section, six models have been conducted with various aspect ratios defined as the depth per the width of the cross-section with a constant number of carbon fiber layers. While the behavior of each aspect ratio in both axial and transverse directions was investigated, the results demonstrate that while the CFRP jackets increase the efficiency of square sections significantly, however, CFRP jacket's effect reduces when cross-section aspect ratio becomes more than 2.0. Secondly, twelve finite element models have been built to study the effect of load eccentricity on the behavior of RC short columns wrapped with external CFRP. The results showed that external confinement can significantly increase the strength of columns under concentric loading, while the enhancement in columns under eccentric loading is not the same. [ABSTRACT FROM AUTHOR]

A variant of the finite element method with Kriging basis functions has been recently developed and applied to plane, plate bending, and shell elastostatic problems. The main advantage of this novel method is that high degree of basis functions can be easily constructed without additional finite element nodes (such as mid-side and inner nodes). This paper revisits the formulation of the Kriging-based finite element method for analysis of curved shell structures, referred to as K-Shell, and presents new numerical tests to shell structures with varying thickness. The K-Shell was formulated based on degenerated 3D elasticity theory. The basis functions were constructed using a set of nodes covering several layers of triangular elements and were employed to approximate both the displacement and geometry. The quartic polynomial basis was chosen to alleviate shear and membrane locking. The K-Shell has been tested using a series of shell benchmark problems with constant shell thickness. The tests showed that K-Shell performed very well in analyzing moderately thick smooth shells. In this paper the K-Shell is tested using two modified shell benchmark problems with varying thickness, i.e. the modified pinched cylinder and the modified hemispherical shell with 18 degrees cut-off. The converged results of three-dimensional finite element model using commercial software Abaqus were used to assess the convergence of the results. The tests show that the performance of K-Shell in analyzing shells with varying thickness is satisfactory. [ABSTRACT FROM AUTHOR]

In the context of the theory of elasticity, the stress state at a sharp notch is singular, and the degree of stress singularity depends on the notch opening angle. Most existing analytical approaches for evaluating asymptotic linear elastic stress fields ahead of V-notches rely on notch stress intensity factors (N-SIFs). This paper presents an alternative analytical approach for evaluating notch stress fields by taking advantage of traction-based structural stress and Williams' eigenfunction methods. To better represent notch stress fields, the first order and higher order terms of eigenfunction are included in the present study. The analytical solutions are then compared to the stress fields resulting from finite element analysis for validation purposes. The stress contours evaluated by the analytical approach are nearly identical to the numerical results corresponding to three distinguishing notch opening angles under pure Mode I loading, which signifies the effectiveness and robustness of the analytical solution methodology developed in the present study. Subsequently, the approach is extended to accommodate Mode II loading by introducing a skew-symmetric term in the stress function. The generalized method is then applied on a welded cruciform joint, which precisely captures the notch fields compared to FEA results. • Developed a robust evaluation approach of linear elastic stress fields around a sharp V-notch under Mode I loading conditions. • Extended the analytical approach to accommodate the presence of Mode II loading. • Validated the analytical approach by FEA under Mode I and combined Mode I and II loading conditions. [ABSTRACT FROM AUTHOR]

Multi-well pressure data from the Magnolia Field, located on a flank of the salt-bounded Titan passive mini-basin in the Garden Banks area of the continental slope of the Gulf of Mexico, indicate remarkably high overpressures that vary, at similar depths, by up to 10 MPa between sand bodies 1 km apart. In the present paper, we integrate geological and geophysical analysis with 2D forward hydro-mechanical evolutionary modelling to assess the contribution of both disequilibrium compaction and diapir-related tectonic loading to the observed overpressure and to understand controls on pressure compartmentalisation. The 2D finite element evolutionary model captured the sedimentation of isolated sand channels bounded by mud-dominated sediments close to a rising salt wall which led to tectonic loading on sediments. Comparison of results from the 2D and 1D models shows that disequilibrium compaction can explain most of the overpressure as a result of very rapid deposition of mainly mud-rich, low permeability sediments; tectonic loading contributes around 7% of the observed overpressure. The models also show that linked to the high sedimentation rates, small variations in the permeability and connectivity of the mud-rich sections that bound the channel sands result in highly compartmentalised pressure distributions in adjacent sand bodies. • Evolutionary hydromechanical simulation of a GoM mini-basin. • Prediction of structure, strain, stress, and overpressure histories. • Quantification of disequilibrium compaction vs tectonically induced overpressure. • Modelling of overpressure compartmentalisation in isolated sand channels. [ABSTRACT FROM AUTHOR]