Showing papers in "Journal of Strain Analysis for Engineering Design in 2017"
TL;DR: In this article, numerical and experimental investigations of autogenous plasma arc welding of thin titanium alloy of 2 mm thick and modelling the temperature distribution for predicting the weld bead geometry are presented.
Abstract: Numerical and experimental investigations of autogenous plasma arc welding of thin titanium alloy of 2 mm thick and modelling the temperature distribution for predicting the weld bead geometry are presented. The finite element code COMSOL Multiphysics is employed to perform non-linear unsteady heat transfer analysis using parabolic Gaussian heat source. Temperature-dependent material properties such as thermal conductivity, density and specific heat are used to enhance the efficiency of simulation process. A forced convective heat transfer coefficient was used to account for the effect of convection. The experimental trials were conducted by varying the welding speed and current using Fronius plasma arc welding equipment. The simulation results are in good agreement with the experimental results.
40 citations
TL;DR: In this article, the slitting method was used to obtain the residual stress in a part and the residual stresses can meaningfully influence on the operation of a part, they are almost created by all fabrication processes.
Abstract: Residual stresses can meaningfully influence on the operation of a part. They are almost created by all fabrication processes. In this study, slitting method was used to obtain the residual stress ...
34 citations
TL;DR: The hole drilling method is a widely known technique for the determination of non-uniform residual stresses in metallic structures by measuring strain relaxations at the material surface caused by hole drilling as mentioned in this paper.
Abstract: The hole drilling method is a widely known technique for the determination of non-uniform residual stresses in metallic structures by measuring strain relaxations at the material surface caused thr...
32 citations
TL;DR: Investigation of differences between superficial and deep pennation angles within each muscle acting over the ankle and predict how differences may influence muscle forces calculated in musculoskeletal modelling found the link between muscle architecture and function contributes to the understanding of the relationship between muscle structure and function.
Abstract: Data about a muscle's fibre pennation angle and physiological cross-sectional area are used in musculoskeletal modelling to estimate muscle forces, which are used to calculate joint contact forces. For the leg, muscle architecture data are derived from studies that measured pennation angle at the muscle surface, but not deep within it. Musculoskeletal models developed to estimate joint contact loads have usually been based on the mean values of pennation angle and physiological cross-sectional area. Therefore, the first aim of this study was to investigate differences between superficial and deep pennation angles within each muscle acting over the ankle and predict how differences may influence muscle forces calculated in musculoskeletal modelling. The second aim was to investigate how inter-subject variability in physiological cross-sectional area and pennation angle affects calculated ankle contact forces. Eight cadaveric legs were dissected to excise the muscles acting over the ankle. The mean surface and deep pennation angles, fibre length and physiological cross-sectional area were measured. Cluster analysis was applied to group the muscles according to their architectural characteristics. A previously validated OpenSim model was used to estimate ankle muscle forces and contact loads using architecture data from all eight limbs. The mean surface pennation angle for soleus was significantly greater (54%) than the mean deep pennation angle. Cluster analysis revealed three groups of muscles with similar architecture and function: deep plantarflexors and peroneals, superficial plantarflexors and dorsiflexors. Peak ankle contact force was predicted to occur before toe-off, with magnitude greater than five times bodyweight. Inter-specimen variability in contact force was smallest at peak force. These findings will help improve the development of experimental and computational musculoskeletal models by providing data to estimate force based on both surface and deep pennation angles. Inter-subject variability in muscle architecture affected ankle muscle and contact loads only slightly. The link between muscle architecture and function contributes to the understanding of the relationship between muscle structure and function.
28 citations
TL;DR: In this paper, the effects of direct tensile response on the flexural resistance of ultra-high-performance fiber-reinforced concretes were investigated by performing sectional analysis.
Abstract: This research investigated the effects of direct tensile response on the flexural resistance of ultra-high-performance fiber-reinforced concretes by performing sectional analysis. The correlations ...
21 citations
TL;DR: One of the important parameters that can influence on performance of a part and its life is residual stress as mentioned in this paper, and all manufacturing processes can create residual stress in different ranges, which can influence the performance of parts and their life.
Abstract: One of the important parameters that can influence on performance of a part and its life is residual stress. All manufacturing processes can create residual stress in different ranges. Laser bendin...
18 citations
TL;DR: In this article, the influence of temperature and strain rate on the mechanical behavior of the high-chromium martensitic steel X20CrMoV12-1 is analyzed.
Abstract: This article aims to analyse the influence of temperature and strain rate on the mechanical behaviour of the high-chromium martensitic steel X20CrMoV12-1. The analysis is based on two series of hig...
17 citations
TL;DR: In this article, the authors studied the end forming behavior of friction stir processed Al 6063-T6 tubes fabricated at different tool rotational speeds and found that the hardness of processed zone increases after end forming operations.
Abstract: The main aim of this work is to study the end forming behaviour of friction stir processed Al 6063-T6 tubes fabricated at different tool rotational speeds. Tube expansion, tube reduction and tube beading are performed on the friction stir processed and parent tubes. The load, thinning and hardness evolution during the end forming operations are evaluated. A rotational speed yielding moderate combination of initial hardness and hardening index of the friction stir processed zone governs the maximum load required during end forming. Tube reduction and tube beading need larger load because of tube thickening, as compared to tube expansion, in which tube thinning is witnessed. The friction stir processed zone of the processed tube undergoes larger thinning and thickening as compared to base material in tube expansion and reduction, respectively, while base material thickens more in tube beading. The hardness and strain hardening exponent difference govern such thickness evolution. Mechanical instabilities like failure of friction stir processed zone, wrinkling and overlapping of friction stir processed zone, and fine cracks development are seen during the end forming operations. The effect of rotational speed on the hardness and grain size distribution of friction stir processed zone is negligible. The hardness of processed zone is found to increase after end forming operations.
14 citations
TL;DR: In this article, an optical fiber-based full-field strain measurement technique was used to investigate delamination growth in laminated composites, and an experimental setup to load the test samples under idealized mo...
Abstract: An optical fiber–based full-field strain measurement technique was used to investigate delamination growth in laminated composites. An experimental setup to load the test samples under idealized mo...
12 citations
TL;DR: In this article, a finite element model of braided wire rope is obtained through mesh generation, and numerical simulation results are analyzed to reveal the stress and deformation distribution rules of the rope strands along the rope axis direction and on the cross sections of strands.
Abstract: To explore the mechanical properties of braided wire rope, relevant theories of differential geometry are applied to deduce the space curve parametric equation of braided wire rope, specific to the structural features of the rope. On this basis, a geometric entity model of YS9-8 × 19 braided wire rope is established. Through mesh generation, a finite element model of braided wire rope is obtained. Constraints and loads are applied for numerical simulation calculations. The numerical simulation results are analyzed to reveal the stress and deformation distribution rules of the rope strands along the rope axis direction and on the cross sections of strands. Tensile tests of YS9-8 × 19 steel wire ropes are performed. The test data and the analogous simulation results coincide, verifying the rationality of the model. The study provides theoretical bases for subsequent frictional wear and life studies on this steel wire rope.
11 citations
TL;DR: There have been many residual stresses measurement methods developed and practiced by researchers as discussed by the authors and they are constantly modified and progressed. Slitting method is one of the most commonly used methods for residual stress measurement.
Abstract: Residual stresses measurement techniques are constantly modified and progressed. There have been many residual stresses measurement methods developed and practiced by researchers. Slitting method i...
TL;DR: In many cases, manufacturers need to form bi-layer sheets to a desired curve by roll bending process and this process can induce... as discussed by the authors The application of Bi-Layer sheets are developing in different industries.
Abstract: Applications of bi-layer sheets are developing in different industries. In many cases, manufacturers need to form bi-layer sheets to a desired curve by roll bending process. This process can induce...
TL;DR: In this article, the effects of variations in temperature and moisture concentrations on the static and free vibration response of sandwich laminated plates with low-density core have been studied, and the results showed that the effect of these variations on the vibration response is independent of the temperature and humidity.
Abstract: In this work, the effects of variations in temperature and moisture concentrations on the static and free vibration response of sandwich laminated plates with low-density core have been studied. A ...
TL;DR: In this paper, the optimal design of isotropic finite plates with different polygonal cutouts under in-plane loading (uniaxial tensile, biaxial, and pure shear load) was pursued by a gray wolf optimization algorithm.
Abstract: This article investigates the optimum design of isotropic finite plates with different polygonal cutouts under in-plane loading (uniaxial tensile, biaxial, and pure shear load). This purpose is pursued by a gray wolf optimization algorithm. The important features of this algorithm include flexibility, simplicity, short solution time, and the ability to avoid local optimums. The objective function used for this algorithm seeks to minimize the value of stress concentration factor around different cutouts. The method used for the calculation of stress concentration is based on analytical solution of Muskhelishvili complex variable and conformal mapping with plane stress assumption. The plate is assumed to be isotropic, linear elastic, and finite (the ratio of cutout side to plate’s longest side in the square and triangular cutouts and the ratio of diameter of circle circumscribing other n-gonals to the plate’s longest side are greater than 0.2). Results show that by selecting the aforementioned parameters pr...
TL;DR: In this paper, the formability of AA5182-O aluminum alloy sheets in the warm working temperature range has been studied, and limit strains of sheets of two different thicknesses have been determined experimentally.
Abstract: Formability of AA5182-O aluminum alloy sheets in the warm working temperature range has been studied. Forming limit strains of sheets of two different thicknesses have been determined experimentall...
TL;DR: In this article, the non-linear postbuckling load-deflection behavior of a tapered functionally graded material beam for different in-plane thermal loadings was studied for two different thermal loads.
Abstract: In the present work, the non-linear post-buckling load–deflection behavior of tapered functionally graded material beam is studied for different in-plane thermal loadings. Two different thermal loa...
TL;DR: In this paper, a series of tensile tests were conducted to validate the volume conservation assumption for aluminum alloy (AA6000) sheet metal, and the results showed that the zero plastic volume change assumption is correct.
Abstract: This article shows an experimental validation of the volume conservation assumption (zero plastic volume change assumption) for aluminum alloy (AA6000) sheet metal. A series of tensile tests were c...
TL;DR: In this article, an experimental method to determine the formability limits by fracture in sheet metal forming is described, which makes use of laboratory test specimens commonly utilized in the mechanical, fracture and formability characterization of sheet materials and involves determination of the gauge length strains at the cracked regions of the specimens after testing.
Abstract: This technical note describes an experimental method to determine the formability limits by fracture in sheet metal forming. The method makes use of laboratory test specimens commonly utilized in the mechanical, fracture and formability characterization of sheet materials and involves determination of the gauge length strains at the cracked regions of the specimens after testing. The presentation explains how measurements are made and what calculations need to be performed in order to determine the fracture forming limit by tension in the principal strain space. The method is applied to Titanium grade 1 sheets, and the fracture forming limit is validated by subsequent experiments with single point incremental forming.
TL;DR: In this article, an improved mathematical model to study the free vibration behavior of rotating functionally graded material beam is presented, considering nonlinearity up to second order for the normal and transverse modes.
Abstract: An improved mathematical model to study the free vibration behavior of rotating functionally graded material beam is presented, considering non-linearity up to second order for the normal and trans...
TL;DR: In this paper, a clear understanding of the influences of bearing geometries on the dynamic performances of roller bearings is presented. But their performance is highly dependent on the bearing geometry.
Abstract: Dynamic performances of roller bearings are greatly affected by their geometries. A clear understanding of the influences of the bearing geometries on the dynamic performances is very helpful for v...
TL;DR: In this paper, changes in spinbond nonwoven fabric structural parameters as functions of deformation are reported, based on micro-photographs of the non-woven fiber structures at various deformation stages and using Fourier transforms.
Abstract: Changes in spunbond nonwoven fabric structural parameters as functions of deformation are reported, based on microphotographs of the nonwoven fabric structures at various deformation stages and using Fourier transforms. The mechanical behavior of the nonwoven structure was considered in relation to three stages of deformation and expressed in terms of the changes in the fiber orientations according to the orientation angle and degree of deformation. With increasing deformation, the fiber orientations in the internal fabric structures correspond to the applied load directions. It was found that the initial stage of deformation with the maximum material stiffness is not accompanied by a significant change in the fiber orientation. However, fiber alignment in the direction of the applied load was observed in the subsequent deformation steps, which are characterized by low deformation stiffness values. An interpretation of the fiber deformation mechanism in the internal structure of the nonwoven fabric was pr...
TL;DR: In this article, a complex potential approach is used to evaluate the contact parameters in Hertzian contact from displacement data, and generic explicit equations for displacement field in the vicinity of the...
Abstract: Evaluation of contact parameters in Hertzian contact from displacement data is studied. Based on complex potential approach, generic explicit equations for displacement field in the vicinity of the...
TL;DR: In this paper, the authors present a failure criteria for sheet metal forming analysis, which is one of the most commonly used failure criteria in sheet metal form analysis, based on the formation limit diagram.
Abstract: Forming limit diagram is one of the most commonly used failure criteria for sheet metal forming analysis. Forming limit diagram generation is time-consuming, and therefore, any reduction in the tes...
TL;DR: In this article, four different grid marking methods, serigraphy, electro-chemical etching, photo-chemi, and photo-chemical, were used for formability tests.
Abstract: Grid marking, which is applied before mechanical tests, is a crucial step in formability tests. In this study, four different grid marking methods, serigraphy, electro-chemical etching, photo-chemi...
TL;DR: In this article, the stress consequences of adding an auxiliary hole in the neighborhood of an original hole are determined from the load-induced thermal information when the geometric discontinuities are sufficient.
Abstract: The stress consequences of adding an auxiliary hole in the neighborhood of an original hole are determined from the load-induced thermal information when the geometric discontinuities are sufficien...
TL;DR: In this article, the authors examined how the physical dimension of samples in in vitro compression tests affects the muscle stress for a given stretch ratio, in both quasi-static and dynamic loading, and proposed that physically larger samples display a higher stress response due to the greater inclusion of complete muscle fascicles and also a reduction in percentage fluid exudation during compression.
Abstract: The stress–strain behaviour of skeletal muscle is affected by many factors, leading to varied results reported in the literature. This article examines how the physical dimension of samples in in vitro compression tests affects the muscle stress for a given stretch ratio, in both quasi-static and dynamic loading. It is proposed that physically larger samples display a higher stress response due to the greater inclusion of complete muscle fascicles and also a reduction in percentage fluid exudation during compression. In the case of quasi-static loading, this was evaluated by testing nominally cubic samples of fresh and aged porcine tissue of characteristic lengths between 10 and 40 mm in compression at 0.05%/s strain in the fibre and cross-fibre directions using a Zwick Z005 universal testing rig. For the dynamic tests, a custom instrumented drop tower test rig was used to achieve average strain rates of 12,500%/s, and the stress responses at stretch ratios of λ= 0.8 and λ= 0.5 of nominally cubic samples ...
TL;DR: In this paper, Lekhnitskii's analysis is used to find closed-form solutions for the distortion of a circular hole in an orthotropic plate under the action of far-field direct and shear stresses.
Abstract: The measurement of residual stress using the deep-hole drilling method relies on the evaluation of the distortion of a hole in a plate under the action of far-field direct and shear stresses While closed-form solutions exist for the isotropic materials, in previous work for orthotropic materials, finite element analysis has been used to find the distortion In this technical note, Lekhnitskii’s analysis is used to find closed-form solutions for the distortion of a circular hole in an orthotropic plate The results are compared with those of finite element analysis for a range of material properties with excellent agreement
TL;DR: In this paper, the authors studied the mechanical behavior of wire ropes and found that axial stress is high and flexural and torsional stresses are relatively low, and they were widely used in applications where the axial and flexional stresses were relatively low.
Abstract: Wire ropes are widely used in applications where the axial stress is high and flexural and torsional stresses are relatively low. Study of their mechanical behavior encompasses many factors, bringi...
TL;DR: In this paper, a modified Neuber's rule is proposed to estimate the inelastic stress and strain at the toe of welded plate connections under large-scale cyclic yielding, caused by the low-cycle fatigue loadings.
Abstract: This article presents a modified Neuber’s rule to estimate the inelastic stress and strain at the toe of welded plate connections under large-scale cyclic yielding, caused by the low-cycle fatigue loadings. In contrast to the original Neuber’s rule, which usually overestimates the notch-tip elastic–plastic stress and strain as the applied nominal stress approaches or exceeds the material yield strength, the modified Neuber’s rule provides a convenient and accurate estimation of the stress and strain at the weld toe as an alternative to the time-consuming numerical computation. The numerical study covers the variations in both the geometric configuration and the material properties in the modified Neuber’s rule. This article also provides closed-form expressions for the two critical parameters in the modified Neuber’s rule to facilitate engineering applications.
TL;DR: In this paper, the Fourier transform and the Laplace transform were used to derive the fundamental solutions for anti-plane elasticity, with the shear modulus and the mass density varying with mass density.
Abstract: In this article, the fundamental solutions for anti-plane elasticity are derived using the Fourier transform and the Laplace transform techniques, with the shear modulus and the mass density varyin...