Finite Element Analysis of Quasi-static Contact Problems Using Minimum Dissipation of the Energy Principle

1994 ◽  
Vol 61 (3) ◽  
pp. 642-648 ◽  
Author(s):  
N. N. Kishore ◽  
A. Ghosh ◽  
S. K. Rathore ◽  
P. V. Kishore

There are many practical situations where two bodies are directly in contact and are subjected to dynamic or varying loads. The contact area and the contact conditions are functions of load and load history and are not known a priori at any load thus making the problems nonlinear. The conditions of contact are determined by the kinematic constraints and the Coulomb’s law of friction. Direct solutions do not give unique results if the load steps are large and the finite element mesh is coarse. In the present work a method using the principle of minimum dissipation of energy is proposed and is applied to finite element analysis of a two-dimensional elastic contact problem under quasi-static loading. A combined incremental and iterative procedure is adopted to solve this problem. The results obtained are in good agreement with physical reasoning. The proposed method obtains new results apart from greatly reducing computational time and efforts.

2021 ◽  
Vol 9 (1) ◽  
pp. 36
Author(s):  
Dong-Ha Lee ◽  
Seung-Joo Cha ◽  
Jeong-Dae Kim ◽  
Jeong-Hyeon Kim ◽  
Seul-Kee Kim ◽  
...  

Because environmentally-friendly fuels such as natural gas and hydrogen are primarily stored in the form of cryogenic liquids to enable efficient transportation, the demand for cryogenic fuel (LNG, LH) ships has been increasing as the primary carriers of environmentally-friendly fuels. In such ships, insulation systems must be used to prevent heat inflow to the tank to suppress the generation of boil-off gas (BOG). The presence of BOG can lead to an increased internal pressure, and thus, its control and prediction are key aspects in the design of fuel tanks. In this regard, although the thermal analysis of the phase change through a finite element analysis requires less computational time than that implemented through computational fluid dynamics, the former is relatively more error-prone. Therefore, in this study, a cryogenic fuel tank to be incorporated in ships was established, and the boil-off rate (BOR), measured considering liquid nitrogen, was compared with that obtained using the finite element method. Insulation material with a cubic structure was applied to the cylindrical tank to increase the insulation performance and space efficiency. To predict the BOR through finite element analysis, the effective thermal conductivity was calculated through an empirical correlation and applied to the designed fuel tank. The calculation was predicted to within 1% of the minimum error, and the internal fluid behavior was evaluated by analyzing the vertical temperature profile according to the filling ratio.


2006 ◽  
Vol 306-308 ◽  
pp. 1151-1156 ◽  
Author(s):  
Chong Du Cho ◽  
Heung Shik Lee ◽  
Chang Boo Kim ◽  
Hyeon Gyu Beom

In this paper, a finite element code especially for micro-magnetostrictive actuators was developed. Two significant characteristics of the presented finite element code are: (1) the magnetostrictive hysteresis phenomenon is effectively taken into account; (2) intrinsic geometric feature of typical thin film structures of large length to thickness ratio, which makes it very difficult to construct finite element mesh in the region of the thin film, is considered reasonably in modeling micro-magneostrictive actuators. For verification purpose, magnetostrictive thin films were fabricated and tested in the form of a cantilevered actuator. The Tb-Fe film and Sm-Fe film are sputtered on the Si and Polyimide substrates individually. The magnetic and magnetostrictive properties of the sputtered magnetostrictive films are measured. The measured magnetostrictive coefficients are compared with the numerically calculated ones.


2007 ◽  
Vol 345-346 ◽  
pp. 525-528
Author(s):  
Shi Jie Wang ◽  
Kang Jian ◽  
Lv Jianhua

Thrust bearing is one of the most important components in esPCP system, which determines the lifespan of the whole system under the restriction of some factors such as the depth of downhole unit, the viscosity of petroleum oil to be pumped. To increase the high temperature bearing ability of the bearings under the limitation of radial size, the damage reason of pre-applied bearings was analyzed. Some different modified plans were put forward from two aspects of structure and material. Contact problems were researched for different plans with finite element analysis software of ANSIS. Comparison of results shows that, in the well of 5½" tube, the optimum selection is ball thrust bearing with 8 balls of radial size of 10mm without keeper.


2000 ◽  
Vol 182 (1-2) ◽  
pp. 17-37 ◽  
Author(s):  
Guang-Di Hu ◽  
P.D. Panagiotopoulos ◽  
Panagouli ◽  
O. Scherf ◽  
P. Wriggers

2004 ◽  
Vol 261-263 ◽  
pp. 687-692 ◽  
Author(s):  
Ahmad Kamal Ariffin ◽  
Syifaul Huzni ◽  
Nik Abdullah Nik Mohamed ◽  
Mohd Jailani Mohd Nor

The implementation of inter-element model to simulate crack propagation by using finite element analysis with adaptive mesh is presented. An adaptive finite element mesh is applied to analyze two-dimension elastoplastic fracture during crack propagation. Displacement control approach and updated Lagrangean strategy are used to solve the non-linearity in geometry, material and boundary for plane stress crack problem. In the finite element analysis, remeshing process is based on stress error norm coupled with h-version mesh refinement to find an optimal mesh. The crack is modeled by splitting crack tip node and automatic remeshing calculated for each step of crack growth. Crack has been modeled to propagate through the inter-element in the mesh. The crack is free to propagates without predetermine path direction. Maximum principal normal stress criterion is used as the direction criteria. Several examples are presented to show the results of the implementation.


2010 ◽  
Vol 3 (S1) ◽  
pp. 139-142 ◽  
Author(s):  
F. I. Pereira ◽  
M. C. Oliveira ◽  
A. Ramalho ◽  
J. L. Alves ◽  
L. F. Menezes ◽  
...  

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