Analytical Scheme for Solid Stress Analysis

2020 ◽  
Vol 12 (06) ◽  
pp. 2050071
Author(s):  
Mohammad Rezaiee-Pajand ◽  
Arash Karimipour

The aim of this paper is to provide a suitable formulation for obtaining an exact answer, for stress analysis of structure with linear elastic behavior. This structure is assumed to be continuous and has unique solution. All the required partial differential equations, namely the equilibrium and compatibility equations, are satisfied. Moreover, the boundary conditions are fulfilled during the solution process. A few available benchmark problems along with some proposal ones are solved analytically, as well as, numerically. Besides, the presented formulas are checked both mathematically and by using a computer program. It is concluded that authors’ scheme offers the advantage of generality and accuracies in comparison to the numerical techniques.

2000 ◽  
Author(s):  
Chris L. Mullen ◽  
Prabin R. Tuladhar

Abstract Discussion of a Performance - Based Engineering evaluation procedure for an existing interstate highway bridge in north Mississippi. The bridge is in a highly trafficked location near the Memphis Metropolitan area and is reflective of modern design practices in Mississippi. Results are presented of nonlinear damage response and displacement ductility performance of the reinforced concrete bents and their foundations predicted using static finite element (FE) computations. The model considers the composite action of the concrete and the reinforcing steel materials under axial force, shear, torsion and flexure. The performance-based evaluation includes three-dimensional computational simulations of the nonlinear bridge system, including substructures and superstructure. The response spectrum dynamic analysis method will also be carried out on the linear elastic three-dimensional model to predict the linear elastic behavior. Field vibration measurements, including ambient and hammer-impact, were performed to calibrate the models. The computed transfer functions are currently being evaluated to correlate vibration measurements and the Finite element models.


2017 ◽  
Vol 119 ◽  
pp. 653-661 ◽  
Author(s):  
Man Zhou ◽  
Dingyi Yang ◽  
Jiandong Zhang ◽  
Lin An

Author(s):  
Sangamesh R. Deepak ◽  
M. Dinesh ◽  
Deepak Sahu ◽  
Salil Jalan ◽  
G. K. Ananthasuresh

The topology optimization problem for the synthesis of compliant mechanisms has been formulated in many different ways in the last 15 years, but there is not yet a definitive formulation that is universally accepted. Furthermore, there are two unresolved issues in this problem. In this paper, we present a comparative study of five distinctly different formulations that are reported in the literature. Three benchmark examples are solved with these formulations using the same input and output specifications and the same numerical optimization algorithm. A total of 35 different synthesis examples are implemented. The examples are limited to desired instantaneous output direction for prescribed input force direction. Hence, this study is limited to linear elastic modeling with small deformations. Two design parameterizations, namely, the frame element based ground structure and the density approach using continuum elements, are used. The obtained designs are evaluated with all other objective functions and are compared with each other. The checkerboard patterns, point flexures, the ability to converge from an unbiased uniform initial guess, and the computation time are analyzed. Some observations are noted based on the extensive implementation done in this study. Complete details of the benchmark problems and the results are included. The computer codes related to this study are made available on the internet for ready access.


2015 ◽  
Vol 1124 ◽  
pp. 209-218
Author(s):  
Pavel Svoboda ◽  
Karl Heinz Winter

Reinforced and pre-stressed concrete have been used increasingly for various kinds of complex structures in the past decades. The structures assembled from panels belong into this group. The current design methods rely on linear elastic analyses based on empirically derived material laws assuming homogeneous and isotropic material. Practical experience and various investigations however have indicated that majority of structures and structural elements are in fact stressed beyond the range of linear elastic behavior. In addition, long term effects may have a significant influence on the structural behavior of this category of structures and structural members.


2007 ◽  
Vol 567-568 ◽  
pp. 225-228 ◽  
Author(s):  
Luboš Náhlík ◽  
Lucie Šestáková ◽  
Pavel Hutař

The objective of the paper is to investigate the direction of a further crack propagation from the interface between two elastic materials. The angle of crack propagation changes when the crack passes the interface. The suggested procedure makes it possible to estimate an angle of propagation under which the crack will propagate into the second material. The assumptions of linear elastic fracture mechanics and elastic behavior of the body with interfaces are considered. The finite element method was used for numerical calculations. The results obtained might contribute to a better understanding of the failure of materials with interfaces (e.g. layered composites, materials with protective coatings) and to a more reliable estimation of the service life of such structures.


Author(s):  
Nurettin Arslan ◽  
Erol Sancaktar ◽  
Mehmet Celik

Abstract The elastic and elasto-plastic stress analysis of thermoplastic matrix roller chain link plates reinforced with steel fibers is performed by using Finite Elements Analysis (FEA). A two-dimensional finite element computer program is developed for elasto-plastic stress analysis. Isoparametric quadratic element with four nodes is used with Lagrange polynomial as an interpolation function. The results of elastic and elasto-plastic finite element stress analysis by using the computer program prepared, are compared with experimental, (photoelastic) results. The spreads of the plastic zones due to the external load applied on the pin-hole of the plate and variations of the residual stresses are determined in different orientation angles and loads. It is shown that the geometry of the link plates can be designed to decrease the stress concentrations. Furthermore, it is shown that the tensile load limit of the roller chain link plate is extended by the residual stresses.


Author(s):  
Harcharan Singh Ranu

Design of an artificial knee was developed using computer 3-D modeling, the high flexion knee was obtained by using a multi-radii design pattern, The increase of final 20 degrees in flexion was obtained by increasing the condylar radii of curvature. The model of the high flexion knee was developed and one of the models was subjected to finite element modeling and analysis. The compositions of components in the artificial knee were, femoral component and the tibial component were metal, whereas the patellar component and the meniscal insert were made using polyethylene. The metal component used for the analysis in this study was Ti6Al4V and the polyethylene used was UHMWPE. Overall biomaterials chosen were: meniscus (UHMWPE, mass = 0.0183701 kg, volume = 1.97518e-005 m3), tibial component (Ti6Al4V, mass = 0.0584655 kg, volume = 1.32013e-005 m3), femoral component (Ti6Al4V, mass = 0.153122 kg, volume = 3.45742e-005 m3), total artificial assembly (mass = 0.229958 kg, volume = 6.75e-005m3). However, in this design the load had been taken to 10 times the body weight. The weight over single knee is only half the maximum load as the load is shared between the two knee joints. Following were the loading conditions, taking average body weight to be 70Kgs and taking extreme loading conditions of up to 10 times the body weight, i.e. 700Kgs on each of the leg performed the Finite Element Analysis (FEA) over the newly designed knee. The loading was done at an increment of 100 Kgs. The loading conditions and the meshing details for the analysis of the assembly were Jacobian check: 4 points, element size: 0.40735 cm, tolerance: 0.20367 cm, quality: high, number of elements: 80909, number of nodes: 126898. A maximum load of 600 Kgs is optimum for this model. The other components observed linear elastic behavior for the applied loads. Based on these results it was determined that the load bearing capacity of the model were well within the failure levels of the materials used for the analysis. A maximum load of 600 Kgs is optimum for this model. The other components observed linear elastic behavior for the applied loads. Based on these results it was determined that the load bearing capacity of the model were well within the failure levels of the materials used for the analysis. Conclusion drawn from this is that for the first time an innovative new design of an artificial knee joint to suite a segment of some religious population has been developed. This allows them to pray, bend in different positions and squat without too much difficulty.


2018 ◽  
Vol 251 ◽  
pp. 03054
Author(s):  
Roman Hurgin ◽  
Nikita Bychkov

Different methods and algorithms are used when conducting research on pipeline hydraulics and their strength calculation. However, processing of the received output is time-consuming and does not allow for expeditious decision on the necessary solution, which in turn leads to the change of the input parameters. The solution to this situation for the designer is to use an automated computer program. The benefits of this approach are the considerable decrease in length of time spent on analysis and ability to see alternatives, for example, change in diameter of the pipe, pipe wall thickness, material for filling the intertubular space and other parameters. In the following article we provide a description of the automated computer program used for scientific research.


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