scholarly journals Determining the exponent of the unloading curve when flattening a sphere

2020 ◽  
Vol 329 ◽  
pp. 03066
Author(s):  
Petr Ogar ◽  
Elena Ugryumova ◽  
Denis Gorokhov

To study the flattening of the sphere, it is proposed to use the kinetic indentation diagram by the plane. Given the known values of the reduced elastic modulus, applied force, maximum and residual deformation, it is possible to determine the contact area. It is indicated that in this regard, the exponent of the unloading curve of a pre-loaded sphere with a flat rigid surface plays an important role. The analysis of methods for determining the unloading curves of unloading for the finite element models, taking into account strain hardening, is carried out. It is shown that dependences of the unloading curves during flattening on the relative indentation in the form and the range of values differ from the similar ones during indentations of the sphere. The dependence between the exponents of the unloading curves for the force and for the area is determined. The range of correct use of the results of the finite element analysis of a hemisphere for rough surfaces is indicated. The exponent of the unloading curve after flattening the spherical segment from the half-space property is determined.

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Zhijun Wu ◽  
Sayed A. Nassar ◽  
Xianjie Yang

This study investigates the effect of the pilot hole size, implant depth, synthetic bone density, and screw size on the pullout strength of the self-tapping screw using analytical, finite element, and experimental methodologies. Stress distribution and failure propagation mode around the implant thread zone are also investigated. Based on the finite element analysis (FEA) results, an analytical model for the pullout strength of the self-tapping screw is constructed in terms of the (synthetic) bone mechanical properties, screw size, and the implant depth. The pullout performance of self-tapping screws is discussed. Results from the analytical and finite element models are experimentally validated.


2014 ◽  
Vol 971-973 ◽  
pp. 781-784
Author(s):  
Hong Lan Liu ◽  
Ning Hu

Based on the RCAR test standards, this paper analyzed the low-speed bumper tests regulations, proposed the design principles of the crash-box and identified the key parameters to evaluate the crashworthiness of the crash-box. This paper built the crash finite element models of the front bumper system, used the finite element analysis software LS-DYNA and HYPERWORKS to simulate the crashworthiness of the crash-box based on different thickness models and completed the performance study of the crash-box. The optimized crash-box has good crashworthiness and it will provide important guidance to the crash-box design.


2011 ◽  
Vol 347-353 ◽  
pp. 4093-4096
Author(s):  
Fu Ting Pan ◽  
Lei Kou ◽  
Cheng Yu Wang

Steel-timber combined member is a new kind of structural member composed of steel core and timber facing with bolt joint.This paper established the finite element analysis models of cantilever beam, and the finite element models were analyzed by the finite element package ANSYS considering the material and geometrically nonlinear.The results were compared with experimental results.Good mechanical properties were verified with comparison between data abtained from the test and calculated results.


2015 ◽  
Vol 1091 ◽  
pp. 83-87
Author(s):  
Xi Bing Hu ◽  
Fei Hua Yi ◽  
Da Long Zhang ◽  
Hui Mao

The finite element models of the planar K-joint are established based on the finite element analysis software ANSYS. The bracing members are under the action of axial force and moment. Different rotational deformation values of the joint with different geometric parameters are reached with calculation and analysis. Results show that the deformation value approximate linearly increased with the increasing load of the bracing member. It also shows that the influence of the bracing member diameter and wall thickness is larger on rotational deformation values and the rotational deformation of the part of the K-joint is greatly influenced by the deformation of joint region.


Author(s):  
Carlos A. Díaz ◽  
Jose J. García ◽  
Christian M. Puttlitz

Spine finite element models are an essential tool to study the degeneration of the intervertebral disc (IVD). Due to the complex geometry of the vertebras, the anisotropy and heterogeneity of the tissues, and the contact and material nonlinearities [1], spine models demand high computational resources. Considering the relatively low stiffness of the IVD compared to that of the vertebrae, we hypothesized that finite element stress and stress distributions of the IVD do not change substantially if the vertebras are modeled as rigid bodies. This simplification in spine models may considerably reduce the solution time when the interest is the analysis of the IVD.


2008 ◽  
Vol 22 (31n32) ◽  
pp. 5949-5954
Author(s):  
HYUN-JUN OH ◽  
EUN-KYUNG LEE ◽  
CHUNG-GIL KANG ◽  
SANG-MAE LEE

In this paper, deformation behavior of Polymethylmethacrylate (PMMA) during thermal indentation was demonstrated by the finite element method using ABAQUS S/W. Forming conditions to reduce the elastic recovery and pile-up were proposed. Thermal nanoindentation experiments were carried out at the temperature range of 110 ~ 150 ° C . The indenter was modeled as a rigid surface. The finite element analysis (FEA) approach is capable of reproducing the loading-unloading behavior for a thermal nanoindentation test and thus comparison between the experimental data and numerical results were demonstrated. The result of the investigation will be applied to the fabrication of the hyper-fine pattern.


2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Ahmet Erklig ◽  
M. Akif Kütük

This study aims to determining the strain gauge location points in the problems of stress concentration, and it includes both experimental and numerical results. Strain gauges were proposed to be positioned to corresponding locations on beam and blocks to related node of elements of finite element models. Linear and nonlinear cases were studied. Cantilever beam problem was selected as the linear case to approve the approach and conforming contact problem was selected as the nonlinear case. An identical mesh structure was prepared for the finite element and the experimental models. The finite element analysis was carried out with ANSYS. It was shown that the results of the experimental and the numerical studies were in good agreement.


1988 ◽  
Vol 16 (1) ◽  
pp. 18-43 ◽  
Author(s):  
J. T. Oden ◽  
T. L. Lin ◽  
J. M. Bass

Abstract Mathematical models of finite deformation of a rolling viscoelastic cylinder in contact with a rough foundation are developed in preparation for a general model for rolling tires. Variational principles and finite element models are derived. Numerical results are obtained for a variety of cases, including that of a pure elastic rubber cylinder, a viscoelastic cylinder, the development of standing waves, and frictional effects.


1985 ◽  
Vol 13 (3) ◽  
pp. 127-146 ◽  
Author(s):  
R. Prabhakaran

Abstract The finite element method, which is a numerical discretization technique for obtaining approximate solutions to complex physical problems, is accepted in many industries as the primary tool for structural analysis. Computer graphics is an essential ingredient of the finite element analysis process. The use of interactive graphics techniques for analysis of tires is discussed in this presentation. The features and capabilities of the program used for pre- and post-processing for finite element analysis at GenCorp are included.


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