scholarly journals Experimental and Finite Element Research on the Failure Mechanism of C/C Composite Joint Structures under Out-of-Plane Loading

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.

2012 ◽  
Vol 568 ◽  
pp. 125-128
Author(s):  
Yu Zhuo Jia ◽  
Li Zhao

In the multiple-circuit on same tower UHV and large crossing transmission tower,The main material of towers usually using a composite section in the form of the dual-angle and four steel angle. Dual-angle and four steel angle connections are inevitable. 500KV Jianbi - Danfeng four circuit transmission line project for the background, Using the finite element software ANSYS10.0, Composite Joints three-dimensional nonlinear finite element simulation. Clear the path of force transferor the node, Mechanical behavior of gusset plate and node failure modes. The results show that: node failure modes for the strength failure, The ultimate bearing capacity of the node is about three times the load of the node design, Node design is relatively conservative, By reducing the thickness of the gusset plate to lower node weight.


2011 ◽  
Vol 332-334 ◽  
pp. 1105-1108 ◽  
Author(s):  
Ling Fei Chen ◽  
Li Chen ◽  
Guo Li Zhang

A 3D finite element model of three-point flexure test of carbon fiber/epoxy composite laminates is developed and analyzed with the finite element software ANSYS. Based on the Hashin criterion, a stiffness degradation method is adopted to predict the progressive failure properties of the carbon fiber/epoxy composite laminates. For carbon fiber/epoxy composite, five failure modes: fiber tensile failure, fiber compressive failure, matrix tensile cracking, matrix compressive cracking and fiber-matrix shear-out failure are included in the present model. The calculated load-displacement curve and the final flexural failure strength are compared with the experimental result, and the finite element results are in good agreement with the experimental values.


2012 ◽  
Vol 510 ◽  
pp. 356-361
Author(s):  
Xu Dan Dang ◽  
Shao Jie Shi ◽  
Yi Guo ◽  
Jun Xiao

The finite element software was used to get the X-cor sandwich’s shear strength. During the shear strength analysis, the failure criterion and materials stiffness degradation rules fitting for the analysis of X-cor sandwich’s failure mechanism were proposed and the X-cor sandwich’s failure process and modes were also clarified. According to the failure criterion we used the elements with stiffness degradation and their distributions in the finite element model to simulate the types and propagation path of the failure and the failure mechanisms of X-cor sandwich under shear were explained. The finite element analysis indicates during the shear firstly the resin regions fail and then the multiple failure modes of Z-pin pull-out from the face-sheet, Z-pin shear off and Z-pin buckling all exist. The propagation paths of the failure elements are dispersive. By contrasting the finite element results and test results the values are consistent well and the error range is -10.4%~7.4%. The comparison results show that the failure criterion and stiffness degradation rules are reasonable and this method can be used to predict the X-cor sandwich’s shear strength.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Peida Hao ◽  
Yanping Liu ◽  
Yuanming Du ◽  
Yuefei Zhang

In situ nanoindentation was employed to probe the mechanical properties of individual polycrystalline titania (TiO2) microspheres. The force-displacement curves captured by a hybrid scanning electron microscope/scanning probe microscope (SEM/SPM) system were analyzed based on Hertz’s theory of contact mechanics. However, the deformation mechanisms of the nano/microspheres in the nanoindentation tests are not very clear. Finite element simulation was employed to investigate the deformation of spheres at the nanoscale under the pressure of an AFM tip. Then a revised method for the calculation of Young’s modulus of the microspheres was presented based on the deformation mechanisms of the spheres and Hertz’s theory. Meanwhile, a new force-displacement curve was reproduced by finite element simulation with the new calculation, and it was compared with the curve obtained by the nanoindentation experiment. The results of the comparison show that utilization of this revised model produces more accurate results. The calculated results showed that Young’s modulus of a polycrystalline TiO2microsphere was approximately 30% larger than that of the bulk counterpart.


2012 ◽  
Vol 197 ◽  
pp. 139-143
Author(s):  
Hua Bai ◽  
Yi Du Zhang

The change of ambient temperature will cause deformation during the machining process of large-scale aerospace monolithic component. Based on finite element simulation, thermally induced deformation of reinforcing plate is studied in such aspects as reinforcement structure, clamping method and temperature change, and contact function in finite element software is used to simulate the unilateral constraint between workpiece and worktable. The results indicate that reinforcing plate will produce warping deformation due to the change of ambient temperature. Different reinforcement structures and clamping methods have important influence on the deformation positions and degrees, and the deformation is proportional to the temperature change.


2021 ◽  
pp. 1-24
Author(s):  
Hamidreza Mahdavi ◽  
Konstantinos Poulios ◽  
Christian F. Niordson

Abstract This work evaluates and revisits elements from the depth-sensing indentation literature by means of carefully chosen practical indentation cases, simulated numerically and compared to experiments. The aim is to close a series of debated subjects, which constitute major sources of inaccuracies in the evaluation of depth-sensing indentation data in practice. Firstly, own examples and references from the literature are presented in order to demonstrate how crucial self-similarity detection and blunting distance compensation are, for establishing a rigorous link between experiments and simple sharp-indenter models. Moreover, it is demonstrated, once again, in terms of clear and practical examples, that no more than two parameters are necessary to achieve an excellent match between a sharp indenter finite element simulation and experimental force-displacement data. The clear conclusion is that reverse analysis methods promising to deliver a set of three unique material parameters from depth-sensing indentation cannot be reliable. Lastly, in light of the broad availability of modern finite element software, we also suggest to avoid the rigid indenter approximation, as it is shown to lead to unnecessary inaccuracies. All conclusions from the critical literature review performed lead to a new semi-analytical reverse analysis method, based on available dimensionless functions from the literature and a calibration against case specific finite element simulations. Implementations of the finite element model employed are released as supplementary material, for two major finite element software packages.


2013 ◽  
Vol 820 ◽  
pp. 151-156
Author(s):  
S.H. Zou ◽  
H.L. Wang ◽  
C.X. Yang ◽  
Y.P. Shi ◽  
J.H. Ge

We expound the finite element simulation and the key points of metal turning by the material properties of the stem in this paper, and select the proper material constitutive equation, then use the adaptive meshing technique, and then finite element modeling was carried out on the valve stem in the professional finite element software Advantedge FEM. The optimization scheme we designed of finite element simulation for the valve stem through the finite element software Advantedge FEM, and we research the influence of the amount of feed and speed cutting process about the cutting force and the cutting temperature.


2013 ◽  
Vol 644 ◽  
pp. 358-361
Author(s):  
Dong Yu Ji

This paper adopts general finite element software to carry out three-dimensional finite element simulation analysis for Huizeli reinforced concrete rectangular-sectioned aqueduct. Considering four combination cases in aqueduct’s construction and operating process, researching variation laws of the aqueduct’s stress and displacement. Analysis results show that design scheme of Huizeli reinforced concrete rectangular-sectioned aqueduct is reasonable, it can meet design requirements. Analysis results provide some theory references for design of reinforced concrete rectangular-sectioned aqueduct.


2011 ◽  
Vol 306-307 ◽  
pp. 733-737
Author(s):  
Xu Dan Dang ◽  
Xin Li Wang ◽  
Hong Song Zhang ◽  
Jun Xiao

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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