scholarly journals Continuum modelling of pantographic sheets for out-of-plane bifurcation and vibrational analysis

Author(s):  
I. Giorgio ◽  
N. L. Rizzi ◽  
E. Turco

A nonlinear two-dimensional (2D) continuum with a latent internal structure is introduced as a coarse model of a plane network of beams which, in turn, is assumed as a model of a pantographic structure made up by two families of equispaced beams, superimposed and connected by pivots. The deformation measures of the beams of the network and that of the 2D body are introduced and the former are expressed in terms of the latter by making some kinematical assumptions. The expressions for the strain and kinetic energy densities of the network are then introduced and given in terms of the kinematic quantities of the 2D continuum. To account for the modelling abilities of the 2D continuum in the linear range, the eigenmode and eigenfrequencies of a given specimen are determined. The buckling and post-buckling behaviour of the same specimen, subjected to two different loading conditions are analysed as tests in the nonlinear range. The problems have been solved numerically by means of the COMSOL Multiphysics finite element software.

Author(s):  
Ye-Chen Lai ◽  
Timothy C. S. Liang ◽  
Zhenxue Jia

Abstract Based on hierarchic shape functions and an effective convergence procedure, the p-version and h-p adaptive analysis capabilities were incorporated into a finite element software system, called COSMOS/M. The range of the polynomial orders can be varied from 1 to 10 for two dimensional linear elastic analysis. In the h-p adaptive analysis process, a refined mesh are first achieved via adaptive h-refinement. The p-refinement is then added on to the h-version designed mesh by uniformly increasing the degree of the polynomials. Some numerical results computed by COSMOS/M are presented to illustrate the performance of these p and h-p analysis capabilities.


2018 ◽  
Vol 11 (4) ◽  
pp. 673-685
Author(s):  
R. C. MATA ◽  
C. S. RAMOS ◽  
M. L. C. SILVA

Abstract This paper presents a numerical analysis of the mechanical behavior of structural masonry panels submitted to horizontal and vertical stresses. To evaluate the design process of these structures, the results obtained by the computer simulations were compared with the results determined by the design criteria of ABNT NBR 15961-1 (2011), ACI TMS 530 (2013) and EN 1996-1-1 (2005). The finite element software DIANA v.9.3 was used to simulate two-dimensional models with the simplified micro modelling procedure. The results obtained by the normative standards were more conservative than the results of the numerical model, as expected. With the increase of the pre-compression level, the computer simulation has demonstrated the increasing trend of the values of resistant forces, besides the change of the way of rupture of the panels. Among the three standards evaluated, the American Standard was the most conservative.


2012 ◽  
Vol 236-237 ◽  
pp. 632-635
Author(s):  
Yue Sun ◽  
Yue Nan Chen ◽  
Zhi Yun Wang

In two-dimensional space, an elasto-plastic finite element computational model was established to simulate inner support for excavation on the basis of the general-purpose finite element software ABAQUS. The soil was assumed to be a uniform and normally consolidated clay layer and strut was discreted by spring element. Compared with published case study, it can be concluded that FEM software AQAQUS can present one reliable simulation progress of inner support for excavation.


2014 ◽  
Vol 989-994 ◽  
pp. 982-985
Author(s):  
Jun Chen ◽  
Xiao Jun Ye

ANSYS-LS/DYNA 3D finite element software projectile penetrating concrete target three-dimensional numerical simulation , has been the target characteristics and destroy ballistic missile trajectory , velocity and acceleration and analyze penetration and the time between relationship , compared with the test results , the phenomenon is consistent with the simulation results. The results show that : the destruction process finite element software can better demonstrate concrete tests revealed the phenomenon can not be observed , estimated penetration depth and direction of the oblique penetration missile deflection .


2015 ◽  
Vol 77 (17) ◽  
Author(s):  
Yasmin Abdul Wahab ◽  
Ruzairi Abdul Rahim ◽  
Mohd Hafiz Fazalul Rahiman ◽  
Leow Pei Ling ◽  
Suzzana Ridzuan Aw ◽  
...  

The non-invasive sensing technique is one of the favourite sensing techniques applied in the process tomography because it has not a direct contact with the medium of interest. The objective of this paper is to analyse the simulation of the non-homogenous system of the non-invasive ERT using finite element software; COMSOL Multiphysics. In this simulation, the liquid-air medium is chosen as the non-homogenous system. A different analysis of the non-homogenous system in term of the different position of the single air, different size of the single air and the multiple air inside the vessel were investigated in this paper. As a result, the location, size and multiple air inside the pipe will influence the output of the non-invasive ERT system. A liquid-gas medium of non-homogenous ERT system will have a good response if the air is located near the source, the size of the air is large enough and it has multiple air locations inside the pipe.


2015 ◽  
Vol 727-728 ◽  
pp. 493-496
Author(s):  
Yun Feng Yao ◽  
Ying Gao ◽  
Jun Xia Li ◽  
Shuang Jie Zhang ◽  
Tao Han

A two-dimensional finite element simulation model of longitudinal welded pipe is established by the nonlinear finite element software ABAQUS. Testing enlargement mould is used for the expanding experiments for the welded pipe under the laboratory condition. The expanding force, ovality and the shape are simulated and measured. Comparing the experimental and the simulated results, the values are fitted well.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2922
Author(s):  
Yanfeng Zhang ◽  
Zhengong Zhou ◽  
Zhiyong Tan

The loading and the failure mode of metal hexagon bolt joints and metal counter-sunk bolt joints of C/C composites were investigated. The joints were tested for out-of-plane loading at two temperatures (600 °C and 800 °C). The failure morphology of a lap plate was investigated, and the main failure modes were determined. The typical load–displacement curve was characterized and the test was simulated using ABAQUS non-linear finite element software. Furthermore, progressive damage was induced, and comparison of the finite element simulation with the experimental data revealed that the failures mainly occurred in the lower lap plate and were dominated by cracking and delamination of the matrix, accompanied by the pull-out of a small number of piercing fibers. Finally, the influences of the temperature, nut radius, and fixture geometry on the critical load were determined via simulation.


2013 ◽  
Vol 353-356 ◽  
pp. 1783-1790
Author(s):  
Qing Li Meng ◽  
Chun Yu Chu ◽  
Jun Chen

The seismic damage and even collapse of the infilled walls in RC frame infilled wall structure is the issue that needs thorough study, In this paper, firstly introduces the improved infilled wall model which can consider the interaction of in-plane and out-of-plane, and can judge the damage state of infilled walls, as well as the interaction between RC frame and infilled walls. Then, based on the finite element software OpenSees, under rare earthquake, performed the nonlinear numerical simulation of two finite element models-RC frame without infilled walls and RC frame with infilled walls, comparative analysis differences of both plastic hinge zone’s steel strain, drift and acceleration response, and in-depth study of the infilled walls effect in RC frame infilled wall structure and reason analysis.


2019 ◽  
Vol 7 (3) ◽  
pp. T647-T656 ◽  
Author(s):  
Mingwen Wang ◽  
Yunqiang Sun ◽  
Gang Luo ◽  
Rui Zhang

Drilling into and around salt bodies can present different kinds of geohazards, such as shrinkage or stuck and crushed casings, resulting in well abandonment and huge economic losses. These engineering disasters are more likely to happen when ignoring the stress perturbations caused by the geomechanical interactions between the salt and surrounding sediments. For a better understanding of the stress perturbations, we use a commercial finite-element software, Abaqus, to build a 2D plane-strain finite-element model of the salt structure of Kuqa depression in the Tarim Basin and simulate the stress perturbations around the salt body in the environment of tectonic compression. By analyzing the patterns of stress perturbations due to different salt geometries such as concave and convex salt, we have come to the conclusion that the convex salt causes compressional stresses on the horizontal and out-of-plane directions but the extensional stress on the vertical direction. On the contrary, the concave salt induces extensional stresses on the horizontal and out-of-plane directions but compressional stress on the vertical direction. The results of stress perturbations near a salt structure in the environment of compressional tectonic stress are opposite to those in the environment of extensional tectonic stress, such as the Mad Dog, in the deepwater northern Gulf of Mexico. The shear stress ([Formula: see text]) near the salt structure is bigger than those far away from the salt structure, but is much smaller when compared with horizontal, vertical, and out-of-plane stresses ([Formula: see text]) in the profile, in the salt body, horizontal stress drops and converges to vertical stress and von Mises stress ([Formula: see text]) equals to zero due to isotropic stresses. The results provide scientific insights on stress perturbations and wellbore drilling design near salt structures in the Tarim Basin.


Algorithms ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 242
Author(s):  
Gujji Murali Mohan Reddy ◽  
Alan B. Seitenfuss ◽  
Débora de Oliveira Medeiros ◽  
Luca Meacci ◽  
Milton Assunção ◽  
...  

Although two-dimensional (2D) parabolic integro-differential equations (PIDEs) arise in many physical contexts, there is no generally available software that is able to solve them numerically. To remedy this situation, in this article, we provide a compact implementation for solving 2D PIDEs using the finite element method (FEM) on unstructured grids. Piecewise linear finite element spaces on triangles are used for the space discretization, whereas the time discretization is based on the backward-Euler and the Crank–Nicolson methods. The quadrature rules for discretizing the Volterra integral term are chosen so as to be consistent with the time-stepping schemes; a more efficient version of the implementation that uses a vectorization technique in the assembly process is also presented. The compactness of the approach is demonstrated using the software Matrix Laboratory (MATLAB). The efficiency is demonstrated via a numerical example on an L-shaped domain, for which a comparison is possible against the commercially available finite element software COMSOL Multiphysics. Moreover, further consideration indicates that COMSOL Multiphysics cannot be directly applied to 2D PIDEs containing more complex kernels in the Volterra integral term, whereas our method can. Consequently, the subroutines we present constitute a valuable open and validated resource for solving more general 2D PIDEs.


Sign in / Sign up

Export Citation Format

Share Document