Three-point bending deflection and failure mechanism map of sandwich beams with second-order hierarchical corrugated truss core

2016 ◽  
Vol 19 (1) ◽  
pp. 83-107 ◽  
Author(s):  
Gang Li ◽  
Yaochu Fang ◽  
Peng Hao ◽  
Zhaokai Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Failure Mechanism ◽  
Failure Modes ◽  
Second Order ◽  
Sandwich Beams ◽  
Plastic Yielding ◽  
Element Analysis ◽  
Three Point Bending ◽  
Truss Core

For sandwich beams with second-order hierarchical corrugated truss core under three-point bending, a correction factor of shear deflection was firstly proposed to improve the prediction accuracy of the bending analysis, which was verified by finite element analysis and compared with the original formula. Then, the failure modes of the sandwich beam under bending were analyzed, including four competing modes of the large struts (i.e. plastic yielding, buckling, wrinkling of facesheet, shear buckling) and two competing modes of the small struts (i.e. plastic yielding, buckling). Subsequently, the analytical expressions of critical load for each failure mode were derived. On this basis, the failure mechanism maps were constructed. Finally, several typical points from the map were selected and verified by finite element analysis, and a good agreement of predicted failure modes was observed.

TTK Chitra tilting disc heart valve model TC2: An assessment of fatigue life and durability

2017 ◽  
Vol 231 (8) ◽  
pp. 758-765 ◽  
Author(s):  
NN Subhash ◽  
Adathala Rajeev ◽  
Sreedharan Sujesh ◽  
CV Muraleedharan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Heart Valve ◽  
Life Prediction ◽  
Heart Valves ◽  
Failure Modes ◽  
Fatigue Life Prediction ◽  
Element Analysis ◽  
Valve Model

Average age group of heart valve replacement in India and most of the Third World countries is below 30 years. Hence, the valve for such patients need to be designed to have a service life of 50 years or more which corresponds to 2000 million cycles of operation. The purpose of this study was to assess the structural performance of the TTK Chitra tilting disc heart valve model TC2 and thereby address its durability. The TC2 model tilting disc heart valves were assessed to evaluate the risks connected with potential structural failure modes. To be more specific, the studies covered the finite element analysis–based fatigue life prediction and accelerated durability testing of the tilting disc heart valves for nine different valve sizes. First, finite element analysis–based fatigue life prediction showed that all nine valve sizes were in the infinite life region. Second, accelerated durability test showed that all nine valve sizes remained functional for 400 million cycles under experimental conditions. The study ensures the continued function of TC2 model tilting disc heart valves over duration in excess of 50 years. The results imply that the TC2 model valve designs are structurally safe, reliable and durable.

Experimental and Finite Element Analysis Approach for Fatigue of Unidirectional Fibrous Composites

2011 ◽  
Vol 87 ◽  
pp. 106-112 ◽  
Author(s):  
Amiri Asfarjani Alireza ◽  
Adibnazari Sayid ◽  
Reza Kashyzadeh Kazem
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Testing ◽  
Micromechanical Model ◽  
Weight Ratio ◽  
Life Time ◽  
Fibrous Composites ◽  
Element Analysis ◽  
Three Point Bending ◽  
The Finite Element Analysis

Fibrous composites are finding more and more applications in aerospace, automotive, and naval industries. They have high stiffness and strength to weight ratio and good rating in regards to life time fatigue. Investigating mechanical behavior under dynamic loads to replace this material is very important. In the present article, investigate Fatigue of Unidirectional Fibrous Composites by using finite element analysis. So, to achieve this purpose Firstly, modeling fiber and matrix in separate case and simulated semi actual conditions, attained S-N curve of fiber and matrix and after that by using micromechanical model of combination fiber and matrix can approach S-N curve of Unidirectional Fibrous Composites. Finally, Comparisons of the finite element analysis of Ansys and the experimental predictions indicate based on three point bending fatigue testing that the results are satisfactorily in good agreement with each other which approves the power law assumption in the model.

Research on the Application of Periodic Truss-Core Structures to Structural Design of Machine Tool

2011 ◽  
Vol 194-196 ◽  
pp. 1977-1981
Author(s):  
Dong Qiang Gao ◽  
Zhi Yun Mao ◽  
Zhong Yan Li ◽  
Fei Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Machine Tool ◽  
Dynamic Properties ◽  
Response Analysis ◽  
Optimized Design ◽  
Element Analysis ◽  
Truss Core ◽  
The Finite Element Analysis ◽  
Harmonic Response Analysis

The modal analysis and harmonic response analysis of the machine tool table with periodic truss-core structures are analyzed and calculated by finite element analysis software-ANSYS Workbench, then we get the finite element analysis results. After comparing the results with finite element analysis results of the original machine tool table, we come to the conclusion that the dynamic properties of the machine tool table with periodic truss-core structures are better than the original machine tool table’s. It makes a base for optimized design and remanufacturing.

Finite Element Analysis of X-Cor Sandwich's Compressive Strength

2011 ◽  
Vol 306-307 ◽  
pp. 733-737
Author(s):  
Xu Dan Dang ◽  
Xin Li Wang ◽  
Hong Song Zhang ◽  
Jun Xiao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compressive Strength ◽  
Failure Modes ◽  
Failure Mechanisms ◽  
Element Model ◽  
Failure Criteria ◽  
Stiffness Degradation ◽  
Element Analysis ◽  
Finite Element Software

In this article the finite element software was used to analyse the values for compressive strength of X-cor sandwich. During the analysis, the failure criteria and materials stiffness degradation rules of failure mechanisms were proposed. The failure processes and failure modes were also clarified. In the finite element model we used the distributions of failure elements to simulate the failure processes. Meanwhile the failure mechanisms of X-cor sandwich were explained. The finite element analysis indicates that the resin regions of Z-pin tips fail firstly and the Z-pins fail secondly. The dominant failure mode is the Z-pin elastic buckling and the propagation paths of failure elements are dispersive. Through contrast the finite element values and test results are consistent well and the error range is -7.6%~9.5%. Therefore the failure criteria and stiffness degradation rules are reasonable and the model can be used to predict the compressive strength of X-cor sandwich.

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