Determination on Interlayer Separation Threshold of Complex Roof with Mechanics Properties

2013 ◽  
Vol 303-306 ◽  
pp. 2908-2913
Author(s):  
De Yi Wu ◽  
Liu Yang Nie
Keyword(s):  
Normal Stress ◽  
Contact Element ◽  
Contact Theory ◽  
Tension Stress ◽  
Deep Mining ◽  
Separation Threshold ◽  
Nonlinear Contact ◽  
Contact Element Method ◽  
Element Method

In order to determine interlayer separation threshold and separation stability of complex roof, distribution of interlayer separation was analyzed in different conditions by a contact element method based on nonlinear contact theory in ANSYS program. The conclusion was drawn that normal stress was tension stress in the center of construction surface in deep mining and it could be considered as interlayer separation threshold of complex roof.

Study and Application on Computational Methods for Ultimate Bearing Capacity of Single Pile

2008 ◽  
Vol 400-402 ◽  
pp. 329-334
Author(s):  
Ze Liang Yao ◽  
Zhen Jian ◽  
Guo Liang Bai
Keyword(s):  
Bearing Capacity ◽  
Computational Methods ◽  
Ultimate Bearing Capacity ◽  
Contact Element ◽  
Computational Formula ◽  
Single Pile ◽  
Foundation Design ◽  
Experiment Method ◽  
Contact Element Method ◽  
Element Method

It is difficult and important to accurately calculate single pile ultimate bearing capacity during pile foundation design. Typical computational methods on single pile ultimate bearing capacity are contrastively analyzed in this paper. Contact element method on single pile ultimate bearing capacity is relatively accurate and economical, but it isn’t used in practical projects until now because its computational process is complicated. 343 different single pile ultimate bearing capacities are calculated with the contact element method in order to study a simple computational formula based on the contact element method. All data calculated are analyzed with a linear recursive multi-analysis program which is programmed with Fortran90. A simple computational formula on the contact element method is presented based on the analysis results. The simple computational formula, the experiential formula in the code, the contact element method and the static load experiment method are respectively used to calculate single pile ultimate bearing capacity in two practical projects in order to test the simple computational formula. The results show that the simple computational formula is relatively accurate. Some advice is presented based on the analysis results.

Computer simulation of landslides by the contact element method

2006 ◽  
Vol 32 (4) ◽  
pp. 434-441 ◽  
Author(s):  
Jiang Xiaoyu ◽  
Qiao Jianping ◽  
Wang Chenghua ◽  
Zhao Yu
Keyword(s):  
Computer Simulation ◽  
Contact Element ◽  
Contact Element Method ◽  
Element Method

scholarly journals USING THE NEW FIBRE CONTACT ELEMENT METHOD FOR DYNAMIC STRUCTURAL ANALYSIS

2015 ◽  
Vol 7 (1) ◽  
pp. 24-38
Author(s):  
João M. C. Estêvão ◽  
Ana S. Carreira
Keyword(s):  
Structural Analysis ◽  
Dynamic Response ◽  
Nonlinear Problems ◽  
Contact Element ◽  
Elastic Response ◽  
Reinforced Concrete Frame ◽  
Structural Dynamic ◽  
Concrete Frame ◽  
Contact Element Method ◽  
Element Method

In literature, there are many methods proposed for structural analysis based on discrete element formulations, mainly for nonlinear problems. One of these new methods is the Fibre Contact Element Method (FCEM). Many of these methods have been used for structural dynamic analysis problems. However, there are some questions about their precision in capturing the dynamic elastic response of structures when comparing to methods based on continuous models, like the well known Finite Element Method (FEM). For this reason, the results obtained with FCEM were extensively compared with FEM results and with laboratorial tests, to better understand the performance of this new method in capturing the elastic dynamic response of structures. Results indicate that this kind of discrete methods are able to determine the vibration modes of a structure with equal or better precision level than the obtained with FEM. FCEM was also used to capture the dynamic response of a reinforced concrete frame with infill walls, as a way to show the method capabilities in reproducing the dynamic behaviour of structures that have an almost continuous mass distribution.

Residual Stress Analysis of Epoxy Coating/Substrate System Using Curvature Measurement Method

2007 ◽  
Vol 345-346 ◽  
pp. 793-796
Author(s):  
Sang Soon Lee ◽  
In Wook Jeon ◽  
Young Chol Chang
Keyword(s):  
Boundary Element Method ◽  
Residual Stresses ◽  
Boundary Element ◽  
Normal Stress ◽  
Measurement Method ◽  
Experimental Result ◽  
Singular Stress ◽  
Curvature Measurement ◽  
Si Wafer ◽  
Element Method

The residual stresses in an epoxy film coated on Si wafer induced during polymerization at room temperature are investigated. The curvature measurement method and the boundary element method (BEM) are employed to investigate the residual stresses. An epoxy film is coated on a relatively thick Si wafer. The normal stress across thickness of the epoxy film is estimated from wafer curvature measurements to be 15- 20MPa . The boundary element method is employed to investigate the whole stresses in the film. The numerical result for the normal stress across thickness of the film, σ xx , shows good agreement with the experimental result obtained by using the curvature measurement method. The singular stress is observed near the interface corner. Such residual stresses are large enough to initiate interface delamination to relieve the residual stresses.

scholarly journals Contact mechanics for soft robotic fingers: modeling and experimentation

Robotica ◽  
2012 ◽  
Vol 31 (4) ◽  
pp. 599-609 ◽  
Author(s):  
Sadeq H. Bakhy ◽  
Shaker S. Hassan ◽  
Somer M. Nacy ◽  
K. Dermitzakis ◽  
Alejandro Hernandez Arieta
Keyword(s):  
New York ◽  
Contact Mechanics ◽  
Weighted Least Squares ◽  
Theory Of Elasticity ◽  
Contact Theory ◽  
Nonlinear Contact ◽  
Different Types ◽  
Least Squares Curve Fitting ◽  
Almost All ◽  
Power Law Equation

SUMMARYHuman fingers possess mechanical characteristics, which enable them to manipulate objects. In robotics, the study of soft fingertip materials for manipulation has been going on for a while; however, almost all previous researches have been carried on hemispherical shapes whereas this study concentrates on the use of hemicylindrical shapes. These shapes were found to be more resistant to elastic deformations for the same materials. The purpose of this work is to generate a modified nonlinear contact-mechanics theory for modeling soft fingertips, which is proposed as a power-law equation. The contact area of a hemicylindrical soft fingertip is proportional to the normal force raised to the power of γcy, which ranges from 0 to 1/2. Subsuming the Timoshenko and Goodier (S. P. Timoshenko and J. N. Goodier, Theory of Elasticity, 3rd ed. (McGraw-Hill, New York, 1970) pp. 414–420) linear contact theory for cylinders confirms the proposed power equation. We applied a weighted least-squares curve fitting to analyze the experimental data for different types of silicone (RTV 23, RTV 1701, and RTV 240). Our experimental results supported the proposed theoretical prediction. Results for human fingers and hemispherical soft fingers were also compared.

A novel nonlinear contact stiffness model of concrete–steel joint based on the fractal contact theory

2018 ◽  
Vol 94 (1) ◽  
pp. 151-164 ◽  
Author(s):  
Yongsheng Zhao ◽  
Hongchao Wu ◽  
Zhifeng Liu ◽  
Qiang Cheng ◽  
Congbin Yang
Keyword(s):  
Contact Stiffness ◽  
Contact Theory ◽  
Steel Joint ◽  
Stiffness Model ◽  
Nonlinear Contact

Analysis of Hygrothermal Stress in Polymeric Thin Film Combining Laser Scanning Method and Boundary Element Method

2006 ◽  
Vol 326-328 ◽  
pp. 625-630
Author(s):  
Sang Soon Lee
Keyword(s):  
Thin Film ◽  
Boundary Element Method ◽  
Residual Stresses ◽  
Boundary Element ◽  
Normal Stress ◽  
Laser Scanning ◽  
Scanning Method ◽  
Polymeric Thin Film ◽  
Hygrothermal Stress ◽  
Element Method

This paper deals with the hygrothermal stress induced in a polymeric thin film deposited on Si wafer subjected to the combined influence of temperature change and moisture absorption. The laser scanning method and the boundary element method (BEM) are employed to investigate the residual stresses. The film/wafer system is assumed to be linearly elastic. The film/substrate system is assumed to be stress-free at a temperature of C o 300 and is cooled from a cure temperature down to room temperature. Then the moisture concentration in the film is increased to the saturation level. The normal stress across thickness of the thin film is estimated from wafer curvature measurements. The boundary element method is employed to investigate the whole stresses in the film. The numerical results for the normal stress across thickness of the film show good agreement with experimental results obtained by using the laser scanning method. The singular stress is observed near the interface corner. Such residual stresses are large enough to initiate interface delamination to relieve the residual stresses.

Sign in / Sign up

Export Citation Format

Share Document