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One of the important soil materials for the evaluation of settlement due to consolidation of soil clay is the compression index (Cc). The assessment of its value through laboratory testing is usually time consuming and expensive. Hence to find the most appropriate model prediction, the paper is examined the compression index comparison with soil plasticity material (water content, liquid limit, plasticity index). The analysis is used by multiple regression analysis and some performance indicators such as Coefficient of Determination (R2), Index of Agreement (IA), Prediction Accuracy (PA), Normalized Absolute Error (NAE) and Root Mean Square Error (RMSE). The result identified the proposed model by Skempton’s, Sidharan, Nagaraj’s and Hough’s are suitable for the compression index (Cc) equation model. Another essential point, the research is found error measurement for soil plasticity index properties. Thus, this prediction model is useful to develop a preliminary assessment of the settlement of structures and carry out suitable action for landslides in Teziutlan, Mexico.

In this study, numerical dynamic analysis of E-glass fiber plain weave composite beams with crack under compression is considered. Before understanding the compression effect on the beam, the dynamic characteristics of the models are compared with the experimental evaluations. Results are given in tabular and graphical form.

The objective of this study is to evaluate experimentally the mechanical compressive strength and static modulus of elasticity of concrete pavers for floors made with iron ore tailings as aggregate concrete. Pavers were manufactured with four different concrete mixtures (cement, natural sand, industrial sand, iron ore tailings, crushed stone), and performed simple compression tests to determine the compressive strength and modulus of elasticity. The pavers manufactured with those concrete mixtures showed greater strength specified by the Brazilian standard. It was possible to find a correlation between modulus of elasticity and compressive strength.

Thermoplastic starch was prepared via compression molding in a stainless steel mold having dimensions of 150 mm x 150 mm x 2mm. Thermoplastic starch was prepared by varying the compression temperature, compression pressure and duration of compression. The starch was extracted from bitter cassava (Manihot esculenta crantz), Datu 1 variety. Tensile properties of the material were found to be dependent on the specific conditions at which molding was done. Factorial analysis showed a significant effect of the temperature-pressure interaction on the tensile strength of thermoplastic starch at 95% confidence level. Thermoplastic starch prepared using the compression molding parameters of 105°C and 6.89 MPa (1000 psi) compression pressure exhibited the highest tensile strength of 464.88 kPa. However, using the molding parameters of 105°C and 6.89 MPa (2000 psi) compression pressure exhibited the lowest tensile strength of 416.64 kPa. Introduction of gelatinizing agents and compression molding up to 105 °C and 13.79 MPa (2000 psi) has partially caused the transformation of the microstructure of starch to a more amorphous state. This is shown by the disappearance of peaks at diffraction angles (2θ) of 12.45° (d1 = 0.71 nm), 14.85° (d2 = 0.6 nm), and 17.04° (d3 = 0.52 nm) and the increase in FWHM value at diffraction angle of 22.94° (d4 = 0.39 nm) from 3.05° (starch) to 11.43° (TPS).

The advantages of aluminum alloy are found expression in lightweight and high strength, while bamboo features in density and thermal insulation. It’s necessary to explore composition effect of bamboo-aluminum composite. Specimens were prepared by filling aluminum alloy hollow profile with bamboo blocks, and then stress-time curves were collected in process of compression. Its ultimate strength reached 56 MPa, and residual strength is about 40% of its ultimate strength. The bamboo-aluminum composite has good mechanical properties and reliability for structural components and is worthy of wide applications.

Numerical studies of buckling failure and debond propagation were carried out on composite sandwich columns with face/core debond. Nonlinear simulations with cohesive elements were carried out by Abaqus 6.14 to predict the buckling modes and debond propagation in sandwich composite columns. For specimens with embedded circular face/core debond, the debond propagated in the interface along the direction which was perpendicular to the compression direction until the through-the-width debond was formed. After that, the face/core debond propagated along the compression direction just as these specimens with through -the-width rectangle debond. Comparisons of the experimental and simulated ultimate loads associated with failure modes showed a good agreement. The maximum error of ultimate load was 10.61%, which proved that the model was capable of predicting accurate buckling loads and post-buckling behaviors.

Flatwise compression and flexural behaviour of perlite/sodium silicate composites made of expanded perlite and sodium silicate is studied using a new manufacturing method for applications of sandwich foam core materials. Sodium silicate content in composites (a perlite particle size of 2-3mm) was varied for a range of 0.1 - 0.3 g/ml and compaction ratio for moulding for a range of 2.0 - 3.0. Specimens under flatwise compression were found to be more capable for energy absorption than those previously reported for lengthwise compression, ascribing to appearance of densification stage following the initial cracking. Also, under flexural loading, energy absorption in composites after the initial cracking was found to be in operation, supporting their candidacy for wide applications where gypsum boards are dominant. It was deduced from both flexural testing results and fracture mechanism that compressive strength is higher than tensile strength, suggesting the future directions of mechanical performance improvement.

Multi‐storied building construction is increasing rapidly throughout the world. Tall buildings more effectively utilize land compared to low rise building. As the height of building increases the importance of lateral load resisting system becomes more relevant than gravity load resisting structural system. Many structural systems are recently introduced to improve the structural performance of tall buildings. Hexagrid system is one among them. Hexagrid system consists of multiple hexagonal grids at the exterior perimeter of the building. It resists both lateral loads and gravity loads by axial stress of their members. The members simply act in tension or compression and show no bending which reduces the need of steel. The paper presents the comparison of different patterns of hexagrid system.

Moderate to strong earthquakes can cause considerable damage to masonry walls which are primary structural elements for decades. In previous earthquakes, a large number of masonry walls failed due to insufficient shear strength with excessive in-plane deformation, or due to insufficient out-of- plane bending capacity of the walls in the perpendicular direction. Typically, out-of- plane failure is far more prevalent and happens earlier than in-plane failure in most past earthquakes. Thus their arises the need to strengthen this masonry walls. Generally, the compressive forces that masonry walls bear vary at different storey’s vary , therefore, walls at lower storey’s can only be applied with relatively smaller prestress due to already higher compression stresses produced by self-weight and floor dead load. Many strengthening methodsSuch as using NSM-CFRP, post tensioning, shortcreting etc. are excellent methods of strengthening masonry walls. In this the performance of post tensioned and reinforced masonry walls is analyzed. Ungrouted, partially grouted, and fully grouted Post Tensioned [PT] Masonry Walls exhibit different behavior and failure mechanisms. For this an analytical model based on an experimental study is prepared and their results are compared with ABAQUS.

For the study of the metal-rubber which is a new material used as damper component. The compression mechanical properties of metal-net rubber were studied. Through the static compression test of metal-net rubber, the influence of some factors such as: compression amount, relative density, wire diameter and bearing area. The method is variable-controlling. Experimental results show that along with the increase of the amount of compression, the nonlinear mechanical properties of metal-net rubber boosts; with the increase of relative density, the compressive capacity of metal-net rubber improves. The wire diameter influences the nonlinear mechanical properties of metal-net rubber, the larger the wire diameter, the compressive capacity is higher; the bearing area is greater, the compressive capacity and energy dissipation performance are better.

Sodium to sodium heat exchanger tubes are small in diameter, long and thin. These tubes are supported at intermediate locations and subjected to compressive and tensile loading during reactor operation. Structural mechanics analyses of a 2-D axi-symmetric model of heat exchanger was performed to estimate the load sharing in these tubes during reactor operation on finite element software ABAQUS. Since the tubes are suppoted at intermediate locations, a 3D model of full tube with intermediate support was made to calculate the critical buckling load and buckling modes. In this paper, structure analysis of heat exchanger and load sharing in tubes, critical load for tube and buckling modes in the tube, and design check of tubes under compression are covered. Tubes which are under compression are checked for buckling and found within the design limit.

The microcrystalline cellulose (MCC) was used as the filler to modify the properties of polyurethane (PU) woodlike material. As we can see from the experimental data, with the gradually increase the amount of MCC added, polyurethane fracture shape variable and the maximum tensile force also increase accordingly, but due to its large density effect on the performance of other, So MCC to improve the effect of polyurethane compression performance is not very big; Through before and after the modification of Fourier transform infrared spectroscopy, the modification of polyurethane materials in amino carbonyl ester peak, so that MCC and polyurethane chemical reaction happened.

This study presents the numerical simulation of a true triaxial test by means of the discrete element method (DEM). Experimental results performed on Toyoura sand are employed as reference and the calibration methodology is explained. Physical aspects of the real soil, such as the grain size distribution and the relative density, are considered during the generation of the virtual sample. It is shown that the main aspects of the macro-mechanical behaviour of granular soils during compression loading can be fairly represented by the idealised simulations with particles.

In this study, we chose 12 commonly available paper towels from the local market. The compression properties of the paper towels were examined by Kawabata Evaluation System for Fabric (KES-F). Three compression properties namely: (i) compressional linearity (LC), (ii) compression energy (WC) and (iii) compressional resilience (RC) were examined. The experimental results revealed that the compression properties varied within the different paper towels. RC vlaue was used as the key property for discussing the compression properties of paper towels. When different compression properties were correlated and analysed, it was found that no relationship was noted within different compression properties. On the other hand, there was not significant statistically relationship between weight and thickness to RC. It is hope that the results from this study can help the indurstry to improve the compression properties of paper towels for local market.

In the paper the main results of numerical study presented in Gambarelli et al. [1] on concrete elements confined by carbon fiber reinforced polymer (CFRP), are overviewed. Furthermore, preliminary results of numerical simulations performed at mesoscale are presented.The numerical study is based on a extensively experimental campaign conducted by Wang and Wu [2] on small CFRP-confined concrete columns loaded in uni-axial compression. The specimens are characterized by constant size but different cross-section corner radius (from square to circular cross section). The experimental results clearly demonstrate that CFRP confinement is much less effective in square then in circular cross-section.Several numerical models have been performed at macro-scale and meso-scale to confirm the predictability of the used numerical approach, based on the microplane constitutive law for concrete [3]. In the finite element model carbon fibers (truss FE) are embedded into matrix (solid 3D FE). The same as for concrete, the constitutive law for matrix is also based on the microplane model.It is demonstrated that the numerical model is able to predict behavior of confined concrete columns from the experimental investigations. Therefore, the results of the study confirm the predictability of the used numerical approach.

Auxetic materials exhibit uncommon behaviour, i.e. they will shrink (expand) laterally under compression (tension). This novel feature has attracted intense research interest. However, most of previous works focus on auxetic behaviour in either compression or tension. Most of the auxetic materials are not symmetric in tension and compression under large deformation. Studies on the auxetic performance of metamaterials both in compression and tension are important but rare. As an extension of our previous research on compressive auxetic performance of 3D metallic auxetic metamaterials, numerical simulations were carried out to investigate the auxetic and other mechanical properties of the 3D metallic auxetic metamaterials in tension. The preliminary results indicated that the designed 3D metallic auxetic metamaterials exhibited better auxetic performance in compression than in tension. By increasing a pattern scale factor, auxetic performance of the 3D metallic auxetic metamaterials under tension can be improved. With proper adjustment of the pattern scale factor, an approximately symmetric auxetic performance could be achieved in compression and tension.

A full scale finite element (FE) analysis has been conducted on aluminum hexagonal honeycomb to investigate its deformation mechanism and mechanical performance under combined compression-shear loads. ANSYS LS/DYNA software has been employed in this numerical study. The honeycomb FE model has the same dimensions (cell size and cell wall thickness) as those used in the previous experimental study. The FE model has been verified by the experimental results. A good agreement between the experimental and numerical results has been reached. This numerical analysis facilitates the measurement of the vertical and horizontal forces applied to honeycomb specimens. The effects of strain rate, plane orientation of cell walls and loading angle on the plateau stress and energy absorption of honeycomb specimens under combined compression-shear loads were investigated.

This paper presents a representative volume element (RVE)-based modelling method to capture the mechanical behaviour of aluminum foams under compressive loadings. Octadecahedron is selected as a geometric basis shape to form closed cells of the aluminum foams in the microstructured RVE model to simulate the mechanical behaviour under compressive loadings. The stress-strain relationship obtained from the numerical modelling is compared to that from experimental study and agreements between these results demonstrate the validity of the proposed RVE model. Through observing the deformation evolution of cells during a compressive loading process, the failure modes of aluminum foams are identified and analysed using the proposed RVE model. Further the influence of strain rate on the mechanical behaviour of aluminum foams under compressive loadings is numerically studied via a parametric study.

Adding braces to moment frames is considered to be quite an efficient technique for increasing the global stiffness and strength of the structure. It has not only been used in steel moment frames, but also in reinforced concrete (RC) moment frames in recent years. It certainly can increase the energy absorption capacity of structures and also decrease the demand imposed by seismic ground motions. Steel braces are anchored firmly to boundary beams and columns. They are modeled as truss elements and increase earthquake resistance of the building. Buckling restrained braced frames (BRBFs) in which members yield under both tension and compression without significant buckling have been used in recent years in order to ensure the desired seismic performance of special concentrically braced frames. BRBFs are similar to the special concentrically braced frames in that seismic accelerations are resisted by a building-frame members and diagonal braces whereas the design procedure is different. BRBs should be designed to permit ductile yielding both in compression and tension. In this paper, flat-slab RC building with two different configurations of buckling restraint braces (BRBs) is studied. The buildings have 4-storey with 5 bays in both X-and Y-directions and have been designed according to Turkish Specification of Reinforced Concrete Design (TS 500). In order to explore overall behavior up to failure and lateral load resisting capacities for these buildings, nonlinear static analyses have then been performed using SAP 2000-V14.1. Pushover analysis under constant gravity loads and monotonically increasing lateral forces during an earthquake until a target displacement is reached is generally carried out as an effective tool for performance based design. The major outcome of a pushover analysis is the capacity curve which shows the base shear vs. the roof displacement relationship and represents the overall performance of the building. The results of the analyses are presented in terms of capacity curve and energy dissipation.

This paper presents analytical and experimental procedures to evaluate the influence of knitted fabrics on the total hand value (THV) for women’s winter thin dress. We examined and compared its mechanical properties, such as tensile, shear, bending, compression, surface roughness and friction properties, measured by the Kawabata Evaluation System for Fabrics (KES FB-Auto), of knitted fabrics with different fiber compositions and different types of knitted structures. The obtained results showed that the knitted structures have significantly influenced on the total hand value (THV) whereas the fiber compositions have shown a less effect on (THV). The existing results prove that the evaluation by KES FB-Auto system has been more beneficial for its basic of mechanical and surface properties. Moreover, the results could be analyzed for its new designing patterns for a refined, comfortable stretch fit.

Computational modelling has been performed to understand the deformation mechanisms of closed-cell aluminium foams under quasi-static compression. A micro-computed tomography-based 3D foam geometry was developed that described the interior of the foam. The FE software ABAQUS/Explicit has been used for the present meso-scale modelling. A good correlation of load-strain response was found between the simulations and experimental results. A sectional view was observed during deformation to explore the internal deformation mechanisms. It was revealed that localized cell collapse occurs due to complex movements of the cell-walls with thin/weaker cells being deformed faster than thick/stronger cells.

The stability analysis of a slender web loaded in compression is presented. The non-linear FEM equations are derived from the variational principle of minimum of potential energy. The peculiarities of the effects of the initial imperfections are investigated using user program. Special attention is paid to the influence of imperfections on the post-critical buckling mode. Stable load-displacement paths are investigated. The FEM computer program using a 48 DOF element has been used for analysis. FEM model consists of 4x4 finite elements. Full Newton-Raphson procedure has been applied.

An article is about mechanical effect of the physic-mechanical material properties on the radial pressure in the compression chamber during the compacting process of wood. Some general methods that describe the transformation process of axial pressure into the radial pressure are shown, As well as the mathematical or experimental methods specifying dependencies and physical conditions. Mathematical finite element method in this area is very useful, but rarely used. Common problems using FEM are the proper definition of the physical material properties in a particular stage of compaction. Material properties are greatly influenced by a number of factors such as moisture, fraction size, chemical composition, current temperature, radial macro structure, axial macrostructure, current pressure and others. The chamber material and the manufacturing processes or the state of wear has an impact on the physical conditions. In terms of tensile elastic deformations, these complex effects reflect and can be merged into several properties. The conversion of axial to radial pressure indicates that some properties of the compacted material have a major impact on the process, such as friction between material and chamber, elastic modulus and Poisson's ratio. The geometry of the pressing chamber also has a significant impact. This paper does not deal so much with the pressing chamber geometry but more so with the characteristics embodied in experimentally measurable quantities. The measurement of these properties in combination with the application of FEM methods proves to be a highly progressive method for understanding the compaction process and the engineering design of compaction machines for the production of briquettes and pellets. The article urges further examination and measurement of a wider range of material properties in the densification process.

This article represents a multidisciplinary approach to biomechanics (engineering + medicine) in the field of distal tibia fractures. The objective of the present study was to carry out a strength and reliability assessment of a medial plate for the treatment of distal tibia fractures. This was performed via numerical modelling (FEM) and experimental methods (compression test and Electronic Speckle Pattern Interferometry – ESPI method). The plate is used for internal fixation in orthopaedics and traumatology. Analyses were performed for non-fused bone with comminuted fracture in the distal metaphysis (i.e. unsuccessful treatment, where all loads in the metaphysis are carried by the plate). An anatomical tibia model (based on CT images in Mimics software) was used for FE analysis. In the experiments, the bone was replaced with a shaped piece of spruce wood (based on Mimics software) and the plate was loaded until its failure (major plastic deformation). Numerical and experimental results were evaluated and compared.

Glass fiber-reinforced lime-based mortars have been studied. Two different fiber reinforcement amounts were used as an addition to the mixtures. Compressive strength and post-cracking behavior of mortars were observed and compared with reference mixture without any reinforcement (marked R). The fibers were added in the amount of 1.8 kg/m3 (mortar samples MA) and 93.75 kg/m3 (mortar samples MB). Destructive compression tests were chosen to compare the performance of the individual mixtures. The maximum compressive strength reached during the testing was the highest for reference samples, while those samples together with MA exhibited the elastic-brittle behavior. Only MB had post-linear hardening behavior and after reaching the maximum compressive strength a slow softening was present.

This paper analyses the uncertainty of pressure measurements in-cylinder and in injection pipe conducted during the studies of a compression ignition engine. Type A and type B evaluations were used to determine the uncertainties of the results. The results are presented for the engine running on diesel or bio-fuel and operating under full load conditions. The results of normality tests provide grounds to reject H0 in some cases. Slightly lower standard uncertainty of the maximum pressure measurement calculated using type A evaluation were acquired for the engine running on bio-fuel.

The monitoring of stiffened composite panels behavior using resistance strain gauges (SG), fibre optic Bragg grating sensors (FOBG) and contactless optical measurements based on digital image correlation (DIC) principle is discussed in the paper. Both the panel structure and different load cases are specified. Mechanical tests include different load-scenarios like static and fatigue loading in compression of reference and impacted panels. The main reason of failure is buckling. The measurements taken from the sensors captured all changes in the buckling modes of the panel. Moreover, they showed a good correlation between FOBG and SG strain measurements.

This thesis deals with the design of a joint for composite flexible elements using an integrated connection. For the verification of the selected layout, a wrapping loop was chosen as a simplified member, which was created on a special form designed for these samples. The material used was unidirectional fibreglass and epoxy resin. These samples were then compared using quasi-static tensile and compression tests. The tests were carried out with the Zwick-Roell Z050 machine. The resulting data of the experiment were then compared with the data obtained from numerical simulations using the finite element system Siemens NX 10 and SIMULIA Abaqus 6.13. 3D strength criteria Maximum stress and direct-mode strength criterion LaRC04 were used for evaluation.

The paper focuses on the assessment of cast-iron columns in industrial heritage structures. For cast-iron structures it is difficult to verify metallurgical composition and processing technology, which directly affect the geometry of cross-sections. The crucial issue of reliability of cast-iron structures is their brittle fracture in tension at higher slenderness ratios. The load carrying capacity of columns is affected by their stability and cast-iron strength in compression and tension. Outcomes of two recently proposed analytical models are compared with extensive experimental data and model uncertainty is quantified. It appears that the model is in a good agreement with experimental data and provides reasonably conservative estimates of load carrying capacity. Outcomes of the study may provide basis for foreseen improvements in calculating buckling coefficient according to ČSN 730038:2014.

Impedance pump is a type of valveless pumping device, in which it utilizes a bio-inspired mechanism for pumping of fluid based on resonant wave interactions along a flexible media. By inducing a periodic asymmetrical compression on the flexible media will produce a unidirectional flow within the system. The impedance pump has many beneficial characteristics which make it an effective driving mechanism, especially for micro-fluidic systems. In addition, the wave-based mechanism through which pumping occurs infers many benefits in terms of simplicity of design and manufacturing. Adjustment of simple parameters such as the excitation frequency or compression location will reverse the direction of flow, providing a very versatile range of flow outputs. This paper describes the experimental analysis of such impedance-driven flow with emphasis on dynamical study of the reverse flow in open-loop environment. In this study, tapered section with converging steps is introduced at both ends of the flexible media to amplify the reverse flow. Study conducted shows that the reverse peak flow is rather significant with estimate of 23% lower than the forward peak flow. The flow dynamics on the other hand has shown to exhibit different characteristics as per the forward peak flow.

This work presents deformation behaviour of gellan gum and gellan gum - bioactive glass composites as novel hydrophilic materials for production of scaffolds in the field of bone-tissue engineering. According to recent studies such materials are attractive for personalized design of implants thanks to their biocompatibility and wide range of available fabrication methods. Batch of samples was subjected to uni-axial compression loading in a custom designed loading device to obtain their elastic and plastic characteristics. However the testing procedure was challenging because of very low stiffness of the material acquired results show a significant reinforcement effect of bioactive glass and its influence to the elastic modulus.

The European Standard [1] for design of concrete compressed slender members shows a significant deficit in global reliability for the design method based on non-linear analysis. The experimental investigation at the Faculty of Civil Engineering SUT in Bratislava was planned for slender concrete columns made of different concrete strength classes - C45/55, C70/85 and C100/115. A basic aim of the analysis was to design concrete columns subjected to bending moment and axial force where the stability failure proceeds at the compression strain 1.5 ‰. The first of three series of experimental and numerical analyzed columns is presented in the paper. The experiments were realized at the Faculty of Civil Engineering SUT in Bratislava with cooperation of ZIPP Bratislava LTD Company.

All segments of the spine are characterized by a corresponding curvature in the sagittal plane and different geometrical parameters of vertebrae, which affects the complicated structure of transition between subsequent segments. The aim of the study was to assess changes occurring in the thoracolumbar spine, as a result of application of the transpedicular fixation. The research was conducted on finite element model, which was constructed on the basis of CT images. Five different configurations of the model were analyzed: focusing on vertebral compression fractures and degeneration of intervertebral discs. The analysis showed that the highest displacement occurred for a segment with intervertebral disc degeneration. Transpedicular fixation of injured thoracolumbar spine is given the opportunity to improve the stability and stiffness of the segment under consideration.

The authors of presented research case focused on possibilities of sealing porous as well as non – porous materials and analysed the measured results. It is the second article of the above mentioned authors dealing with sealed joints, however, in this case study the focus was placed on a group of industrially manufactured modified silyl polymer and polyurethane sealants. The research is based on the modified test procedure for the determination of adhesion and cohesion properties during maintained extension at variable temperatures, i.e. a high temperature of (70 + 2) °C and a temperature simulating freezing, i.e. (-20 + 2) °C, according to the European standard EN ISO 9047. The degree of specimen extension was set to amplitude of 20.0 % and the aim of the research case was to discover any differences that might appear in the resistance. The measured results demonstrate that there are significant differences between individual sealants in the results they provide in combination with specific material, e.g. wood appears to be a problematic substrate as well as glass cement or aluminium.

In this work parametric modelling was utilized to design and produce two types of porous microarchitectures with auxetic compressive properties suitable for deformation energy mitigation applications such as blast and bullet protection. The samples were directly produced from acrylic material using a high resolution 3D printer and their compressive mechanical characteristics were tested. Two different structures exhibiting in-plane negative strain dependent Poisson’s ratio were selected for the analysis: i) two-dimensional inverted (re-entrant) honeycomb and ii) two-dimensional cut missing-rib. Stress-strain relationships were established from a set of quasi-static compression experiments where the strain fields were evaluated using digital image correlation applied to measure the full-field displacements on the samples' surface. From the displacement fields true strain – true stress curves were derived for each sample and relative elastic moduli were evaluated.

Carbon fibre reinforced plastic (CFRP) composite materials has unique mechanical and functional properties due to the combination of its constituent materials that possesses desirable properties. The present paper focuses on analysis of surface roughness in drilling of fly ash filled carbon fibre reinforced composites produced through compression moulding route. Experiments are conducted on a radial drilling machine using Taguchi’s experimental design. Drilling test is carried out using coated HSS drill of 6 and 10 mm diameter. The effect of drill diameter, wt % of fly ash, spindle speed and the feed rate are investigated on surface roughness. The relative significance of the various parameters has been found using ANOVA.

The distribution and the size of longitudinal dynamic forces that develop in the train body found in braking system are influenced by the length of the train. To determine these forces, it is used a mechanical model consisting of rigid bodies, representing the train vehicles, connected by elastic and damping elements with the nonlinear characteristic that shapes the buffer and draw-gear. The results based on numerical simulations highlight the emergence of dynamic longitudinal forces during braking, their evolution over time and the distribution of maximum compression and stretching forces that develop in buffer and draw-gear devices, for different lengths of the passenger train.

The paper originally investigates the influence of the admitted ranges of slow-acting filling time of brake cylinder on longitudinal dynamics of freight trains, using experimental air pressure data obtained in tests on filling characteristics. Mechanical and pneumatic models are summarized and numerical simulations were performed for a train composed of six wagon train, in different filling characteristics configurations. The results reflect significant effects on in-train forces values, while evolution and disposition of compression and tensile forces between neighbored vehicles in the long of the train are also affected.

Looking for new applications of the available materials, such as magnetorheological elastomers (MERs) is an important element of machine design process. To this end it is necessary to determine their fundamental mechanical properties, including Young’s modulus and shear modulus. These properties are determined experimentally by testing the material in compression, tension and shear. In the case of the analysed group of materials the above-mentioned constants depend, inter alia, on the parameters of magnetic field acting on them. Therefore, it is necessary to determine the character and the extent of variation of the mechanical properties as a function of the physical constants characterising the active magnetic field, namely magnetic flux and magnetic intensity (field strength).This paper presents the results of static compression tests carried out on magnetorheological elastomers. The parameters measured during the static compression test were force and displacement at a pre-set magnetic flux. The maximum strength of the induced magnetic field was limited by the design parameters of the test set-up. In order to determine the behaviour of the material at greater values of magnetic strength and flux the properties of a real material were modelled with a neural network. The simulation was carried out using a simple, one-layer neural network. The chosen network training approach was error backpropagation. This approach enables approximation and predicting of changes of the properties of the tested material. The output results will enable deriving an analytical model of the tested MREs.

There are situations in the thin-walled steel girders with box intersection, in which the internal wall of compression flange is elastically restrained in the webs of section and along its length occurs the change of normal stresses. Such a wall was modelled, as a bilateral elastically restrained internal plate variably loaded at the length. Explicit formulation of neural formula on buckling coefficient of internal plate at non-linear distribution of longitudinal stress was discussed in this paper. A few structures of neural networks (NN) were envisaged in order to obtain the best of the numerical effectiveness of the final formula. The results noted from the literature were used for the evaluation of neural prediction of coefficient.

Aim of this present work is to study the combined effect of distributed geometric global imperfection and a local dent on buckling strength of thin square plates subjected to uni-axial compression. Steady state non linear FE analysis including both material and geometrical non linearities is used to determine the ultimate strength of the dented plates. From the numerical result it is found that in case of low thickness plates global geometric imperfections effect is more dominant and in case of thick plate dent effect is found to be more dominant.

Rigid polyurethane (PU) foams were prepared with palm oil based polyols (POP) and methylene diphenyl diisocyanate (MDI) in order to archieve rigid formulations. The effect of the different amount of MDI (1 wt.%, 1.1 wt.% and 2 wt.%) were studied in density, compressive strength and energy absorption. It was found that the higher compressive strength of the PU foams showed at 1.604 MPa whereas the amount of MDI increased to 1.1 wt. %. The increased amount of MDI to 2 wt.% showed the higher value in density (0.0531 kg/m3) and energy absorption with 46.490 J for 70 % displacement.

The manufacturing of steel gears by cold forging can be realized by using the so called Samanta process. The present study focuses on the one hand on the FE based analysis of the forming of gears in forward extrusion and on the other hand on the modelling of a Samanta process, using the software Simufact.forming. Thereby the influence of different tool geometries and the tribological conditions on the forming are investigated. The aim is to obtain a basic understanding of the material flow and the filling of the tooth cavity depending on the geometry of the Samanta process. For the investigations the common heat-treatable steel 1.7131 (16MnCr5) was used. As an input parameter for the simulation the true stress-true strain curve of the material has been determined within compression tests. For the analysis of the forming the material flow into the cavities and the shape of the tooth flanks are evaluation criteria. Thus the influence of the different parameters on the distribution of equivalent plastic strain, the forming and the reachable accuracy have been investigated.

The combinations of polymer resin and glass microballoon are the main materials used to produce syntactic foams. Syntactic foam is a lightweight material that has good mechanical properties and is commonly used as a component for structural materials in civil construction, aerospace and marine applications. Hence, it should have suitable mechanical properties, particularly good compression behaviour. In the present study, the results obtained from compression tests are compressive strength, elastic modulus and specific compression that decrease when increasing of glass microballoon contents (2.0 wt.%, 4.0 wt.%, 6.0 wt.%, 8.0 wt.% and 10.0 wt.%) and also neat resin. The highest strength value for compression testing is owned by 2.0 wt.% which is 88.9 MPa, while the lowest strength is 43 MPa that belongs to 10.0 wt.% of glass microballoon. This shows that the density and weight percentage of glass microballoon in these syntactic foams affect compression properties. Therefore, a further study should be conducted, which includes the effect of compressive failure mechanism.

Biopolymer made from renewable material is one of the most important groups of polymer because of their versatility and they can be manufactured in a wide range of densities, damping and stiffness. In this project, biopolymer based from waste vegetable oil were synthesized and crosslinked with commercial polymethane polyphenyl isocyanate and doped with titanium dioxide (TiO2) to produce renewable polymer foam (RPF).The RPF was compressed by using hot compression moulding technique at 90 °C based on the evaporation of volatile matter and is known as compressed renewable polymer (CRP). The compressive strength, compressive modulus, absorption energy, static stiffness, vibration and damping characteristic of RPF and CRP were determined. The compressive strength and compressive modulus of RPF and CRP samples steadily increased with increasing of TiO2loading. The highest compressive strength of RPF and CRP samples is at 10 % of TiO2loading of 96.43 kPa and 354.55 kPa, respectively due to the amount of filler loading. The absorption energy and static stiffness of CRB allows it to absorb more energy than RPF due to the smaller cell size and higher density. The vibration and damping characteristic of both samples were generated at displacements of 1 mm and acceleration of 0.1 G base excitation according to ASTM D3580-9. It was revealed that, the vibration transmissibility characteristic of RPF and CRP samples slightly increased and damping characteristic is vice versa with the increasing of percentages of TiO2loading at the frequency range of 15 - 25 Hz.

It is well-known that superimposed ultrasonic tool vibrations are capable of decreasing the forming force and the interfacial friction during the deformation of metal. The complex causes of this phenomenon were mainly investigated by focusing on oscillation frequencies above 20 kHz. Due to limitations of the load capacity and the power of the oscillating systems, mostly soft materials, such as aluminium and copper, were analysed. The present study is concerned with the development of a tool system for ultrasonic-assisted compression tests with a 15 kHz oscillation system. The advantages of this type of oscillating system are an increased power and robustness, which allow the testing of high strength materials. In preliminary ultrasonic-assisted compression tests with a S235JR steel a force reduction of up to 63 % was measured. The major challenges identified during the preliminary investigations are a transversal drift of the specimen, a periodic separation between the die and the specimen, a high sound emission and a high demand on the measuring and signal processing technology. Based on the technical challenges and the determined requirements a tool system is introduced.

The new manufacturing technology sheet-bulk metal forming (SBMF) combines the sheet metal forming and bulk metal forming techniques. At the Institute of Forming Technology and Machines (IFUM), a new multistage SBMF process is being developed. In order to reduce the friction and improve the dimensional accuracy of the parts, superimposed oscillation is used within the new SBMF process. SBMF processes allow the manufacturing of solid metal components out of flat steel. To analyse the effect of friction on the superimposed oscillating SBMF process more precisely, superimposed oscillating and non-oscillating ring compression tests at room temperature were carried out. Like the semi-finished products for SBMF process the ring specimens were cut out of a sheet plate by water jet cutting. A new tool system with an integrated hydraulic oscillation system was developed for superimposed oscillating compression of the ring specimens. This tool system enables the absorption of the forming force and displacement stroke of the ring specimen during the ring compression test. After the practical experiments, the force profiles of superimposed oscillating and of non-oscillating process were compared. The influence of the frequency on the surface roughness of ring specimens was investigated. Furthermore, the tribological conditions of the superimposed oscillating ring compression test were analyzed.

The purpose of this study was to analyze the behavior of a lumbar spine disc prosthesis with different materials. The study was performed at L4-L5 lumbar motion segment using the finite element method (FEM). A healthy Finite Element (FE) model was used as a reference with which to compare the results of the FE simulations of the artificial discs. The healthy and the artificial FE models were subjected to a combination of 0.5 MPa Compression pre-load and 10Nm of Flexion moment. The artificial FE models were based on Maverick artificial disc, and the three materials proposed for study the artificial disk were Titanium, Ceramic and CrCoMo alloy. The most suitable material for developed the artificial disc was the CoCrMo alloy due to: The von Mises stresses on the bone with which this artificial disc was in contact were reduced as much as possible and also, were very similar to the von Mises stresses obtained in the bones from the healthy disc.

The objective of the study was to design a simulation model that approximates the real viscoelastic behavior of spinal units in stress relaxation tests. The spinal units were sampled from porcine and used in fresh condition, without frizzing or drying. The mechanical tests were conducted on Mecmesin5i testing machine using the appropriate devices for compression tests. On the other hand, using Maxwell constitutive equation for relaxation, a Simulink model was created. At the end, the relaxation curve derived from the simulation model was draw next to experimental obtained data in order to represent the fitting.

The cold flow field in a two dimensional cavity of supersonic combustor has been simulated numerically by using the compressible flow Navier-Stokes equation with theκ-ωSST turbulence model. The flow field structure of different cavity aft wall slope angle (16°,30° and 90°) , different fore aft wall height ratio (1 and 2) and different length depth ratio (3 and 5) are analyzed. The conclusions are as follows: As cavity aft wall slope angle decreases, the compression wave formed at cavity leading separation corner shifts into expansion wave, the shear layer moves into cavity gradually; As cavity fore aft wall height ratio increases from one to two, the expansion wave formed at cavity leading separation corner strengthens and there is no compression wave formed at;As cavity length depth ratio increases from three to five, the compression or expansion wave formed at cavity leading separation corner weakens, cavity bottom wall pressure tends to be constant and aft wall pressure rises.