scholarly journals Elastic plastic analysis of shallow shells—a new approach

2005 ◽  
Vol 47 (1) ◽  
pp. 121-130
Author(s):  
J. Mazumdar ◽  
A. Ghosh ◽  
J. S. Hewitt ◽  
P. K. Bhattacharya
Keyword(s):  
Plastic Deformation ◽  
Efficient Method ◽  
Plastic Bending ◽  
New Approach ◽  
Shallow Shells ◽  
Elastic Plastic ◽  
Aspect Ratios ◽  
Contour Lines ◽  
Plastic Analysis

AbstractA simple and efficient method for the analysis of the elastic-plastic bending of shallow shells is presented. The method is based upon the concept of contour lines of equal deflection on the surface of the shell, and uses Illyushin's theory of plastic deformation. As an illustration of the method, a technically interesting example of a shallow elliptic elastic dome is examined. Results are obtained for increasing loads and varying aspect ratios, and are illustrated graphically. The application of the method to other shell geometries is quite straightforward.

The New Approach to the Analysis of Elasto-Plastic Deformation of Solids Within the Bounds of Theory of Processes by A. A. Ilyushin

2001 ◽  
Author(s):  
Kamal Sh. Babamuratov ◽  
Rustam A. Abirov
Keyword(s):  
Plastic Deformation ◽  
Complex Loading ◽  
New Approach ◽  
Elastic Plastic ◽  
Computer Complex ◽  
Loading Method

Abstract In this report results of systematic researches of the experimental-theoretical CL-computer (complex loading) method, offered by Ilyushin for solving of problem of strength and strains of elastic-plastic bodies at an incomplete theoretical information about the equations of relation between stresses and strains and the method of appraisal of reliability of plasticity problems’ solution are given. Homogeneous and nonhomogeneous problems for element of construction in form of the rods, plates, shell are accomplished. The results of numerical and CL experiments indicate on perspectivity of considered methods for calculations and projection of responsible designs in an engineering and building.

An Elastic-Plastic Solver of the Wheel-Rail Contact

2010 ◽  
Author(s):  
Constantin I. Ba˘rbiˆnt¸a˘ ◽  
Sulleyman Yaldiz ◽  
Alina Dragomir ◽  
Spiridon S. Cret¸u
Keyword(s):  
Plastic Deformation ◽  
Stress State ◽  
Plastic Material ◽  
Computer Code ◽  
Load Level ◽  
Analysis Model ◽  
Elastic Plastic ◽  
Circular Arcs ◽  
Plastic Analysis ◽  
Perfect Plastic

Wheel and rail in service undergo continual wear and plastic deformation at the surface, so that in time all wheel profiles will be different. The optimization by grinding a worn rail profile to minimize contact stresses requires the development of a software to reconstruct a rail profile using circular arcs. A working algorithm, able to be incorporated into a computer code, has been developed to solve the stress state in the general case of non-Hertzian contacts. To limit the pressure, an elastic-perfect plastic material has been incorporated into the computer code. The pressure distribution and the corresponding stresses states have been investigated for pure normal loadings, as well as for the combined, normal and tangential loadings. The elastic-plastic analysis model allows fast investigations regarding the influence of different parameters such as load level, contact geometry including the geometry of the worn profiles.

Study on Piping Response Under Multiple Excitation Validation for Elastic-Plastic Analysis of Piping

2014 ◽  
Author(s):  
Satoru Kai ◽  
Tomoyoshi Watakabe ◽  
Naoaki Kaneko ◽  
Kunihiro Tochiki ◽  
Makoto Moriizumi ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Seismic Response ◽  
Nuclear Power ◽  
Time History ◽  
Large Earthquake ◽  
Response Analysis ◽  
Analysis Method ◽  
Elastic Plastic ◽  
History Analysis ◽  
Plastic Analysis

Piping in a nuclear power plant is usually laid across several floors of a single building or adjacent buildings, and is supported at many points. As the piping is excited by a large earthquake through multiple supporting points, seismic response analysis by multiple excitations within the range of plastic deformation of piping material is necessary to obtain the precise seismic response of the piping. The verification of the dynamic analysis method of piping under an elastic domain, which is excited by multiple seismic inputs, was performed in our study last year and the correspondence of a piping response between an analysis and an experiment have been confirmed [17][18]. However, few experiments under plastic deformation conditions have been performed to verify the validity of multiple excitation analysis under a plastic deformation range. To obtain better understanding of the behavior of piping under a large seismic input, it is important to investigate the seismic response by multiple excitations and to verify the validity of the analytical method by multiple excitation experiments. This paper reports the validation results of the seismic elastic-plastic time history analysis of piping compared with the results of the shaking test of a 3-dimensional piping model under a plastic deformation range using triple uni-axial shake table. Three directional strains from the analysis and the experiments were compared in order to validate the analysis method. As a result, it is confirmed that the elastic-plastic analysis by time history excitation shows good agreement with the test results.

Simplified Methodology for Analysis of Reflected Detonation and DDT: Part 2 — Elastic-Plastic Analysis

2014 ◽  
Author(s):  
Thomas C. Ligon ◽  
David J. Gross ◽  
John C. Minichiello
Keyword(s):  
Plastic Deformation ◽  
Time History ◽  
Initial Pressure ◽  
Elastic Response ◽  
Detonation Pressure ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Modeling Methodology ◽  
Plastic Analysis ◽  
Unburned Fuel

This paper applies a simplified conservative approach for analyzing elastic-plastic response of piping due to reflected gaseous detonations and deflagration-to-detonation transitions (DDT). A consequence associated with gaseous explosions is the potential for DDT to occur near the end of a closed pipe or gas pocket. As an accelerating deflagration flame approaches a closed end, the unburned fuel ahead of the flame front is compressed to an elevated initial pressure. This process is often referred to as pressure piling or pre-compression, and the combination of detonation reflection with the elevated initial pressure can produce extremely high peak pressures and large values of impulse. In this paper, the event where DDT occurs immediately ahead of the reflecting surface is referred to as a reflected-DDT (R-DDT). Due to the extreme pressures that R-DDTs can achieve, the piping can frequently experience elastic-plastic deformation. In this second part, the pressure time-history modeling methodology developed for elastic response in part one is extended to elastic-plastic analysis. The inelastic response of the piping material is modeled using a lower-bound strain hardening curve at a single representative strain rate. The pressure model is compared to a published reflected detonation pressure model for the stoichiometric mixture of ethylene and oxygen, and finite-element analysis results using the simplified methodology are compared to two recent sets of published plastic deformation data from ethylene oxygen explosion tests in austenitic stainless steel tubing and piping.

Elastic-Plastic Analysis and Failure Assessment of the Pipeline Steel with Surface Crack

2012 ◽  
Vol 602-604 ◽  
pp. 2245-2248
Author(s):  
Zhong Xian Wang ◽  
Rui Feng Zhang
Keyword(s):  
Surface Crack ◽  
Biaxial Loading ◽  
Pipeline Steel ◽  
Assessment Method ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Aspect Ratios ◽  
Biaxial Load ◽  
Failure Assessment ◽  
Plastic Analysis

A detailed elastic-plastic analysis on different semi-elliptical surface crack geometries under uniaxial and biaxial load was conducted using 3D finite element analysis for pipeline steel X100. After quantitating fracture driving force J-integral and plastic yielding load, the effects of biaxial load and crack geometry were investigated by using the Option 3 of R6 failure assessment diagram approach for the surface cracks with the different crack sizes ( aspect ratios c/a = 1, 1.5 and 3 ) and the various biaxial loading ratios λ from -1 to 2. And three option curves of the R6 assessment were compared to evaluate the applicability of R6 assessment method for the X100 steel.

Research on Strength Design of Channel Clips for Suspended Ceilings

2018 ◽  
Vol 774 ◽  
pp. 223-228 ◽  
Author(s):  
Shinichi Enoki ◽  
Yuki Shibayama ◽  
Mitsuru Saito ◽  
Junichi Ito ◽  
Yasunori Nakamura ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Design Method ◽  
Equivalent Stress ◽  
Large Earthquake ◽  
Efficient Design ◽  
Simple Method ◽  
Elastic Plastic ◽  
Mechanics Of Materials ◽  
Strength Design ◽  
Plastic Analysis

Suspended ceilings consist of ceiling boards, furring channels, channel clips, furring brackets, hangers and ceiling bolts. The ceilings are easy to drop down when the large earthquake occurred. The channel clips deform and disengage from the ceilings or break at that time. Design engineers calculate and evaluate the stress in the clips by using method with mechanics of materials. The evaluation depends on the experiences of the engineers. Mechanics of materials is considered in elastic region, but the channel clips are in plastic deformation. Therefore, after the design, the clips are manufactured and are subjected to verification tests as the design evaluation. Sometimes the prototype tests become multiple times. The purpose of this research is to build a simple method of an efficient design for the channel clips. It is ordinary to use elastic-plastic analysis at strength design in the case of plastic deformation. But software for elastic-plastic analysis is expensive, so the design method of the channel clips depends on the elastic stress analysis function of 3D CAD in this research. Instead, we designed and evaluated the equivalent stress corresponding the tensile strength in plastic deformation as the evaluation criterion. As a result, it was possible to evaluate the design that the channel clips are not broken when assuming earthquake occurrence with a seismic intensity of 7. This evaluation is reliable compared to the verification test conducted in the past.

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