Asymptotic analysis of an adhered complete contact between elastically dissimilar materials

2014 ◽  
Vol 49 (8) ◽  
pp. 607-617 ◽  
Author(s):  
Hyung-Kyu Kim ◽  
David A Hills ◽  
Robert JH Paynter
Keyword(s):  
Asymptotic Analysis ◽  
Half Plane ◽  
Stress Singularity ◽  
Dissimilar Materials ◽  
Element Model ◽  
Load Combination ◽  
Mode Separation ◽  
Generalized Stress Intensity Factors ◽  
Complete Contact ◽  
Specific Material

A complete contact problem between elastically dissimilar materials is studied using an asymptotic analysis. A quarter plane wedge on a half-plane represents the contact edge geometry. Two eigenvalues are obtained for pairs of contacting materials, and their characteristics are classified on the Dundurs parallelogram. Generalized stress intensity factors, KI and KII, are derived to use a two-term stress equation of dimensionless form with developing a mode separation angle. It is found that the order of stress singularity increases as the wedge becomes more rigid than the half-plane. Slipping characteristics on the contact interface are investigated in detail, especially for the case of KI < 0 < KII that represents a typical adhesive complete contact condition. An example case is given using a finite element model to provide calibration of the stress intensities for a specific material, geometry and load combination.

Numerical simulation of thermal properties at Cu/Al interfaces based on hybrid model

2015 ◽  
Vol 32 (3) ◽  
pp. 574-584
Author(s):  
Yunqing Tang ◽  
Liqiang Zhang ◽  
Haiying Yang ◽  
Juan Guo ◽  
Ningbo Liao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Bonding Temperature ◽  
Dissimilar Materials ◽  
Element Model ◽  
Potential Method ◽  
Interfacial Thermal Resistance ◽  
Interfacial Region ◽  
Fe Model ◽  
Content Type

Purpose – The purpose of this paper is to investigate thermal properties at Cu/Al interfaces. Design/methodology/approach – A hybrid (molecular dynamics-interface stress element-finite element model (MD-ISE-FE) model is constructed to describe thermal behaviors at Cu/Al interfaces. The heat transfer simulation is performed after the non-ideal Cu/Al interface is constructed by diffusion bonding. Findings – The simulation shows that the interfacial thermal resistance is decreasing with the increase of bonding temperature; while the interfacial region thickness and interfacial thermal conductivity are increasing with similar trends when the bonding temperature is increasing. It indicates that the higher bonding temperature can improve thermal properties of the interface structure. Originality/value – The MD-ISE-FE model proposed in this paper is computationally efficient for interfacial heat transfer problems, and could be used in investigations of other interfacial behaviors of dissimilar materials. All these are helpful for the understanding of thermal properties of wire bonding interface structures. It implies that the MD-ISE-FE multiscale modeling approach would be a potential method for design and analysis of interfacial characteristics in micro/nano assembly.

Evaluation of Adhesive Joints of Two Different Materials

2012 ◽  
Author(s):  
M. M. Islam ◽  
Rakesh K. Kapania
Keyword(s):  
Finite Element ◽  
Dissimilar Materials ◽  
Element Model ◽  
Lap Joints ◽  
Adhesive Joints ◽  
Cohesive Zone Modeling ◽  
Stress Distributions ◽  
Test Fixture ◽  
Zone Modeling ◽  
Nonlinear Finite Element Model

In a test-fixture that the authors were using, steel tabs adhesively bonded to an aluminum panel debonded before the design load on the real test panel was fully applied. Therefore, studying behavior of adhesive joints for joining dissimilar materials was deemed to be necessary. To determine the failure load responsible for debonding of adhesive joints of two dissimilar materials, stress distributions in adhesive joints as obtained by a nonlinear finite element model of the test-fixture were studied under a gradually increasing compression-shear load. It was observed that in-plane stresses were responsible for the debonding of the steel tabs. To achieve a better understanding of adhesive joints of dissimilar materials, finite element models of adhesive lap joints and Asymmetric Double Cantilever Beam (ADCB) were studied, under loadings similar to the loading faced by the test-fixture. The analysis was performed using ABAQUS, a commercially available software, and the cohesive zone modeling was used to study the debonding growth.

Numerical investigations of the clinching process and the failure prediction of clinched joints for dissimilar sheets

2021 ◽  
pp. 095440622110250
Author(s):  
Qihan Li ◽  
Chuanwei Xu ◽  
Song Gao ◽  
Fenglei Ma ◽  
Qingming Zhao ◽  
...  
Keyword(s):  
Prediction Model ◽  
Aluminium Alloy ◽  
Tensile Force ◽  
Dissimilar Materials ◽  
Element Model ◽  
Fracture Load ◽  
Tensile Failure ◽  
Good Prediction ◽  
Axial Tensile ◽  
Dimensional Finite Element

The clinching process is more and more used in automotive design and manufacturing. Traditional quality inspection of joints needs a lot of destructive tests, which is time-consuming and material-consuming. In this paper, the clinching process and joints failure of dissimilar materials, 6061 aluminium alloy and HC340/590DP dual-phase steel, are studied. A two-dimensional finite element model is established. Experiments were carried out to verify the numerical model. Through the axial tensile test, the quality of clinched joints for upper steel-lower aluminium alloy and upper aluminium alloy-lower steel were measured, respectively, and the strength and safety of the joints met the requirements of design indexes. The conventional prediction model of maximum tensile force and its modified model was researched. Combined with numerical simulation results, the fracture load, the separation load, and the failure mode of two clinched joints were predicted, respectively. Furthermore, the results are in good agreement with the experimental results. The results show that the modified prediction model of maximum tensile force has a good prediction result, and the error rate is less than 10%. The modified prediction model of maximum tensile force can effectively predict the tensile failure test results, which provides a basis for the quality evaluation and strength prediction optimization of dissimilar materials clinched joints.

Asymptotic analysis of the corner-behaviour of a rigid punch bonded to an elastic substrate

2007 ◽  
Vol 42 (5) ◽  
pp. 415-422
Author(s):  
L Bohórquez ◽  
D. A Hills
Keyword(s):  
Stress Field ◽  
Plastic Zone ◽  
Asymptotic Solution ◽  
Asymptotic Analysis ◽  
Half Plane ◽  
Poisson's Ratio ◽  
Rigid Block ◽  
Rigid Punch ◽  
Oscillatory Behaviour ◽  
Elastic Substrate

The contact between a flat-faced rigid block and an elastic half-plane has been studied, showing that an asymptotic solution correctly captures the stress field adjacent to the contact corners for all values of Poisson's ratio. It is shown that, in practical cases, the plastic zone, which is inevitably present at the contact corners, envelopes the oscillatory behaviour implied locally but is surrounded by an elastic hinterland correctly represented by the asymptote.

Structural Design of the Geometrical Shape of Interfaces in Bonded Dissimilar Materials Based on Theoretical Elastic Analysis

1999 ◽  
Vol 586 ◽  
Author(s):  
Masayoshi Tateno ◽  
Yasushi Fukuzawa ◽  
Shigeru Nagasawa ◽  
Hiroshi Sakuta
Keyword(s):  
Stress Distribution ◽  
Structural Design ◽  
Bonding Strength ◽  
Stress Singularity ◽  
Dissimilar Materials ◽  
Correlation Factor ◽  
Geometrical Shape ◽  
Elastoplastic Behavior ◽  
Secant Stiffness ◽  
The Relationship

ABSTRACTIn order to evaluate the practical strength of a joint and its fracture mode, it is important to find the stress distribution near the edge of the interface by analyses of strength and fracture. The index of stress singularity based on theoretical analysis is a useful tool to indicate the stress distribution.In this paper, investigations on the evaluation of the practical strength of bonded dissimilar materials based on the stress singularity are carried out. The secant stiffness module, which was used for plastics analysis, was applied to the evaluation of thermal elastoplastic behavior near the interface. Spherical conditions of the interface shape were used for the evaluation of stress behavior and the experiment of bonding strength. The relationship between the index of stress singularity, λ, and the practical strength of the bonded TiB2-Ni system was investigated by comparing theoretical λ, which was determined by substituting the secant stiffness module into Bogy's eigenequation, with the practical strength in the edge angle of the interface between 60° and 90° The correlation factor of the relationship between λ and the practical bonding strength of the TiB2-Ni system was found positive. These results show that the structural design of a geometrical interface which is getting a higher strength joint based on the index of stress singularity is verified experimentally.

Evaluation of Strength on Dissimilar Metal Joints for ITER First Wall Components

2010 ◽  
Author(s):  
H. Nishi ◽  
M. Enoeda ◽  
T. Hirose ◽  
D. Tsuru ◽  
H. Tanigawa
Keyword(s):  
Heat Flux ◽  
Stainless Steel ◽  
Stress Singularity ◽  
Dissimilar Materials ◽  
High Heat ◽  
High Heat Flux ◽  
First Wall ◽  
Cu Alloy ◽  
Quarter Plane ◽  
Plane Joint

The first wall (FW) of ITER blanket includes beryllium (Be) armor tiles joined to CuCrZr heat sink with stainless steel cooling tube and backing plate in order to improve plasma performance and reduce thermal stress. Therefore dissimilar materials joints are indispensable for fabricating the high heat flux components. Since these joints must withstand thermal and mechanical loads caused by the plasma and electromagnetic force, it is important to evaluate the strength and thermal fatigue life of dissimilar materials joints. When the dissimilar materials joints are subjected by external force and thermal loading, the stress of the joint may indicate singularity at the interface edge. Since the stress singularity may lower the strength of joints, the singularity is evaluated numerically for the various materials combinations and joint configuration to be used in high heat flux components of fusion reactors in this investigation. Moreover, tensile test and elasto-plastic FEM analysis are performed to investigate the fracture behavior of Be/Cu alloy and stainless steel/ Cu alloy obtained the FW mock-up. The results reveal two singular solutions of type rpj−1 for a half-plane bonded to a quarter-plane joint and the singularity is larger than that of a bonded quarter-planes joint. From the viewpoint of stress singularity, the configuration of bonded quarter-planes joint is better than the half-plane bonded to a quarter-plane joint. The singularity for W/Cu alloy combination is large compared to other combination of materials. Especially the singularity of stainless steel/ Cu alloy is very small. Tensile specimen of Be/CuCrZr joint fractured at the bonding interface due to the stress singularity. For the stainless steel/ Cu alloy, however, the specimens fractured at the Cu alloy region apart from the interface.

The Effects of Materials Properties & Angle Junction on Stress Concentration at Interface of Dissimilar Materials

2011 ◽  
Vol 383-390 ◽  
pp. 887-892
Author(s):  
Alireza Fallahi Arezoodar ◽  
Ali Baladi
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Stress Reduction ◽  
Stiffness Matrix ◽  
Stress Singularity ◽  
Dissimilar Materials ◽  
Element Analysis ◽  
Materials Properties ◽  
Main Factors ◽  
Elastic Modules

In dissimilar material joints, failure often occurs along the interface between two materials due to stress singularity. Stress distribution and its concentration depend on materials and geometry of the junction as the stress concentration depends on grain orientation and its stiffness matrix of neighboring grains in micro-scale. Inhomogenity of stress distribution at the interface of junction of two materials with different elastic modules and stress concentration in this zone are the main factors resulting in rupture of the junction. Effect of materials properties, thickness, and joining angle at the interface of aluminum-polycarbonate will be discussed in this paper. Computer simulation and finite element analysis by ABAQUS showed that convex interfacial joint leads to stress reduction at junction corners in compare with straight joint. This finding is confirmed by photoelastic experimental results.

Study on FEM Analysis of Multistory Steel Frame Structure and its Optimal Design

2012 ◽  
Vol 433-440 ◽  
pp. 2194-2200
Author(s):  
Ru Wang ◽  
Long Qin ◽  
Zhen Qi Shao
Keyword(s):  
Optimal Design ◽  
Parametric Design ◽  
Fem Analysis ◽  
Element Model ◽  
Steel Frame ◽  
Frame Structure ◽  
Structural Element ◽  
Load Combination ◽  
Section Size ◽  
Steel Frame Structure

An finite element model (FEM) of multistory steel frame structure is established by applying ANSYS parametric design language(APDL) in this paper, where the objective function of optimization is defined as the minimum volume of a Pin framework. The optimal design are carried on by applying the optimized toolbox of ANSYS, based on analysis the situation of the most disadvantageous load combination. Several approaches have been proposed to avoid restraining to the local minimum. Experimental results show that the section size of the structural element improved obviously.

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