scholarly journals Finite Element Simulations of Dynamic Shear Fracture of Hollow Shear Pins

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Zibo Jin ◽  
Jin Zhou ◽  
Daochun Li

The shear pin structure is widely used in aeronautics and astronautics structures to deal with emergency structure separation problems. The shear pin design has a strict restriction on the precise failure load and definite failure mode. Previous research has conducted shear fracture tests and simulations of solid shear pins while there is a lack of detailed research on the shear fracture of hollow shear pins with large diameters. In this research, a 3-dimensional finite element model was built based on the actual shear pin installed on the aircraft engine pylon and the model was validated by the experiment. The influences of the inner diameter of hollow shear pins on the shear fracture process were investigated by conducting finite element simulations. The structural deformation, energy dissipation in the fracture process, and failure load of shear pins were evaluated. It is found that as the inner diameter increases, the failure mode of shear pins changed and would result in difficulties on the structure separation. To solve this problem, a new configuration of hollow shear pin was proposed for the purpose of obtaining both desired failure load and failure mode. The new configuration was verified by the fracture simulation and it is found that the new configuration is effective and can be used to improve the shear fracture performance.

Author(s):  
Jun Yan ◽  
Cuncun Jiang ◽  
Zhirui Fan ◽  
Qi Xu ◽  
Hongze Du ◽  
...  

The rapid development of additive manufacturing technology provides a new opportunity for the fabrication and research of multi-layer lattice sandwich structures, and thereby some excellent performances can be further discovered. Based on the manufacturing-experiment-analysis technical route, the failure mode of the additive manufactured aluminum multi-layer alloy lattice sandwich structure under quasi-static compression is systematically studied in this paper. Through the combination of experimental observation and finite element analysis, the complex failure mechanism of the multi-layer lattice sandwich structure is revealed. The results show that the multi-layer lattice sandwich structure under quasi-static compression conditions mainly manifests as a layer-by-layer failure mode of the internal lattice structure, which includes the yield, plastic buckling and material damage. At the same time, in comparison with the force–displacement curve and the structural deformation in the key locations, the analysis accuracy of the finite element model can be verified by the compression experiment. Based on the verified finite element model, the most significant influence of different face panel thicknesses, as well the rod radiuses and tilting angles on the energy absorption (EA) is identified via sensitivity analysis. Furthermore, size factors on the structural EA are revealed. This study can provide a helpful guidance for the design of multi-layer lattice sandwich structures in practical applications.


2011 ◽  
Vol 264-265 ◽  
pp. 1654-1659 ◽  
Author(s):  
Tasneem Pervez ◽  
Sayyad Zahid Qamar

This paper presents the finite element analysis of tubular expansion in oval bore holes such as those frequently observed in Upper Natih reservoirs. The minimum inner diameter of the expanded tubular must be larger than the drift diameter set by American Petroleum Institute (API) standards. If the minimum inner diameter is smaller than drift diameter, completion equipments can not be run successfully, which is necessary to complete an oil-well for production. The phenomenon of tubular ovality has been previously unknown to petroleum industry. Finite element model of tubular expansion in oval bore-holes is developed to determine the tubular ovality and compared with measured ovality. It was found that ovality increases linearly with tubular expansion ratio. With increase in expansion ratio, the tubular contact length with formation and developed contact pressure increases. Tubular ovality, if not considered in well design, may lead to premature tubular failure due to lower collapse rating and higher stresses.


2011 ◽  
Vol 105-107 ◽  
pp. 38-42
Author(s):  
Jian Liang Yu ◽  
Xing Qing Yan ◽  
Ling Chen

Finite element model of the elbow interiorly impacted by flat-nosed missile was established using ANSYS/LS-DYNA. The Cowper-Symonds model was adopted. The rupture strain failure criterion was used to define the failure process. Numerical values were compared with experimental values obtained from the literature and the reliability of model was validated. The penetration failure mode of the elbow was analyzed. Factors of the critical rupture kinetic energy Er were acquired. It can be seen that the penetration failure mode is plugging induced by the extrusion and scraping dominated of axis stress. The effect of Do on Er can be neglected. Er increases with the increase of t/Do, Dm/t and R/Do when the missile mass m is invariable. The effect of m on Er should consider the factors of m and critical rupture velocity Vr.


2000 ◽  
Vol 27 (4) ◽  
pp. 785-797 ◽  
Author(s):  
Z W Guan ◽  
P D Rodd

Brittle premature failure caused by splitting parallel to the timber grain is a common failure mode in glulam joints made with solid dowel type fasteners. It is thought that this problem can be alleviated by using hollow steel dowels as the fasteners and reinforcing the timber locally in the area of the joint. In this way, by varying the wall thickness of the dowels and the thickness of the reinforcing members, a chosen combination of strength and stiffness should be attainable together with a ductile failure mode. In this paper, three-dimensional nonlinear finite element models are developed to simulate (i) the structural performance of a timber joint made with a single hollow steel dowel and (ii) a moment transmitting joint made with a number of the dowels, each type being locally reinforced by densified veneer wood. The models incorporate suitably defined elastoplasticity and orthotropic elasticity and also allow for large deformations of the joints as well as for frictional contact between the timber and the dowel. They are calibrated against physical test data from joints loaded to failure.Key words: glulam, densified veneer wood, resin injected, hollow dowel fastener, moment transmitting, ductile failure, finite element.


2014 ◽  
Vol 501-504 ◽  
pp. 1297-1300
Author(s):  
Hai Yun Huang ◽  
Jun Ping Zhang

An on-site static load test of a reinforced concrete double-arch bridge with fracture is carried out, and a comparative analysis of the measured experimental results of the bridge working conditions and the calculation results of Midas/civil Finite Element Model is performed. The results show that the performance and structural deformation recoverability of the bridge is weak. The bridges overall load-bearing capacity does not satisfy its designed requirements.


2021 ◽  
Author(s):  
Menghan Wang ◽  
Yifeng Chen ◽  
Yan Han ◽  
Lei Li ◽  
Menglong Du

Abstract Aiming at the problems of low strength and unsatisfactory connection quality of plastic clinching of heterogeneous lightweight materials for the cars body, the Q235 steel sheets, and 5052 aluminum alloy sheets were taken as the research objects, and the inclined wall die for plastic clinching was designed based on the deformation and flow characteristics of sheets in the plastic clinching process. The elastic-plastic finite element numerical simulation and experimental research were used to analyze the plastic clinching process of the inclined wall die, and the failure mode and mechanism of the clinching joints in the shear and peel experiment were deeply studied. The results show that the inclined wall die can effectively increase the interlock value of the joints and reduce the maximum joining force during the clinching process under the condition of ensuring the neck thickness of the joints. When the inclined wall angle α increases from 90° to 100°, the interlock value increases by 38.9%, and the maximum joining force decreases by 8.3%. The influence of inclined wall structure on joint quality can be divided into extrusion stage, radial inflow stage, and stability stage. The comparison between the clinching experiment and the finite element results shows that the two results are in good agreement, which proves that the finite element model of plastic clinching of inclined wall die has a high degree of credibility, and verifies the feasibility of practical application of inclined wall die. Finally, under shear and peel loads, the main failure mode of the joints is separation failure.


2013 ◽  
Vol 41 (2) ◽  
pp. 82-108 ◽  
Author(s):  
James M. Gibert ◽  
Balajee Ananthasayanam ◽  
Paul F. Joseph ◽  
Timothy B. Rhyne ◽  
Steven M. Cron

ABSTRACT When competing in performance with their pneumatic counterparts, nonpneumatic tires should have several critical features, such as low energy loss when rolling over obstacles, low mass, low stiffness, and low contact pressure. In recent years, a nonpneumatic tire design was proposed to address each of these critical issues [1]. In this study, the steady state and transient energy losses due to rolling resistance for the proposed nonpneumatic tire are considered. Typically, such an analysis is complex because of the coupling of temperature on the structural deformation and the viscoelastic energy dissipation, which requires an iterative procedure. However, researchers have proposed a simplified analysis by using the sensitivity of the tire's elastic response to changes in material stiffness through a deformation index [2–4]. In the current study, the method is exploited to its full potential for the nonpneumatic tire due to the relatively simple nature of deformation in the tire's flexible ring and the lack of several complicating features present in pneumatic tires, namely, a heated air cavity and the complex stress state due to its composite structure. In this article, two models were developed to predict the transient and steady-state temperature rise. The first is a finite element model based on the deformation index approach, which can account for thermo-mechanical details in the tire. Motivated by the simplicity of the thermo-behavior predicted by this finite element model, a simple lumped parameter model for temperature prediction at the center of the shear band was developed, which in many cases compares very well with the more detailed finite element approach due to the nature of the nonpneumatic tire. The finite element model can be used to, for example, explore the design space of the nonpneumatic tire to reach target temperatures by modifying heat transfer coefficients and/or material properties.


2016 ◽  
Vol 710 ◽  
pp. 396-401 ◽  
Author(s):  
Ze Chao Zhang ◽  
Hong Bo Liu ◽  
Xiao Dun Wang ◽  
Xiang Yu Yan ◽  
Jing Hai Yu ◽  
...  

The upper part of Caofeidian coal storage was approximately hemispherical aluminum shell, covered with aluminum alloys plate. The capsule was made of aluminum alloys material, and its span was 125 meters. In the design, according to TEMCOR joint, we used the finite element software MIDAS to build the accurate geometry models and calculation models of aluminum alloys single layer latticed dome structures. By the combination of constant loads, live loads, snow load, wind load, temperature effect and other working conditions, we summarized the consumption of aluminum of the structures, and studied the structural internal force, structural deformation and structural stiffness. In addition, the X and Y two different direction seismic dynamic load was applied to the structure. The structural seismic performance under two kinds of modes were studied through the structure mode analysis of the vibration frequency. The vierendeel dome and single layer dome were controlled by the stability. ANSYS three-dimensional frame element model were set up, and the eigenvalue buckling analysis was carried out. By the geometrical nonlinear finite element method, combining with initial imperfections and material nonlinear, we found out the stability coefficient and the weak parts of the structure.


2012 ◽  
Vol 204-208 ◽  
pp. 1109-1117
Author(s):  
Hui Peng ◽  
Shu Yu Yu ◽  
Chun Sheng Cai ◽  
Wei Wei Liu

The bonding behavior of CFRP-concrete interface has important influence on the mechanical behavior and the failure mode of the strengthened structure. In this paper, a total of 4 specimens strengthened with CFRP plate were prepared and the double-shear tests were conducted to investigate the mechanical behavior and the failure mode of the CFRP-concrete bonding. During the tests, the on the ultimate bearing capacity and the distribution of the CFRP strains were measured and the influence of bonding lengths and thickness of the epoxy were discussed. According to the test results, the distribution of the CFRP strain along the bonding length shows an exponential decreasing law, and the strain in the vicinity of the loading position was much greater than that at the ends. Based on the test data, the finite element model of the specimens was developed, by using the orthotropic spring elements to simulate the adhesive layer with ANSYS software. The comparison of the analytical results and the experimental results indicates that both results have shown a good agreement.


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