An Experimental and Modeling Study of Thermal Cyclic Behavior of Sn-Cu and Sn-Pb Solder Joints

1993 ◽  
Vol 323 ◽  
Author(s):  
Y.-H. Pao ◽  
S. Badgley ◽  
R. Govila ◽  
E. Jah
Keyword(s):  
Solder Joints ◽  
Cyclic Behavior ◽  
Temperature Cycle ◽  
Beam Specimen ◽  
Finite Element Program ◽  
Creep Properties ◽  
Cyclic Shear ◽  
Double Beam ◽  
Element Program ◽  
Hysteresis Response

AbstractThermal cyclic shear stress/strain hysteresis response of 97Sn-2Cu-0.8Sb-0.2Ag, 95.5Sn-4Cu-0.5Ag, 63Sn-37Pb, and 62Sn-36Pb-2Ag solder joints have been determined using a double beam specimen. The temperature cycle had a period of 40 minutes and extreme temperatures of 40°C and 140°C.The steady state creep properties of these solders were determined, and the associated Norton's law was implemented in a finite element program to simulate the experiment. The fatigue life of these solders joints and failure mechanism are also discussed.

Constitutive Behavior and Low Cycle Thermal Fatigue of 97Sn-3Cu Solder Joints

1993 ◽  
Vol 115 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Y.-H. Pao ◽  
S. Badgley ◽  
E. Jih ◽  
R. Govila ◽  
J. Browning
Keyword(s):  
Steady State ◽  
Constitutive Equation ◽  
Thermal Fatigue ◽  
Solder Joints ◽  
Steady State Creep ◽  
Creep Mechanism ◽  
Beam Specimen ◽  
Finite Element Program ◽  
Cyclic Shear ◽  
Element Program

The thermal cyclic shear stress/strain hysteresis response and associated steady-state creep parameters of 97Sn-3Cu solder joints have been determined using a beam specimen previously developed by Pao et al. (1992a). The solder joint was subjected to a 40-minute thermal cycling from 40°C to 140°C. A constitutive equation based on elastic and steady-state creep deformation for the solder has been formulated and implemented in a finite element program, ABAQUS, to model the experiment. The results show that the constitutive equation based on one single creep mechanism cannot fully account for the deformation during cooling, as opposed to the case of 90Pb-10Sn where the entire cyclic deformation can be well modeled by a similar constitutive equation (Pao et al., 1992c). This suggests that another creep mechanism is dominant for lower stresses and higher temperature. The thermal fatigue results show that the failure mechanism of 97Sn-3Cu joints is similar to that of 90Pb-10Sn joints, but the number of cycles to failure of 97Sn-Cu solder joints is at least 5 times longer than 90Pb-10Sn solder joints. This indicates the potential application of 97Sn-3Cu in place of 90Pb-10Sn solder.

A Nonlinear and Time Dependent Finite Element Analysis of Solder Joints in Surface Mounted Components Under Thermal Cycling

1991 ◽  
Vol 226 ◽  
Author(s):  
Yi-Hsin Pao ◽  
Kuan-Luen Chen ◽  
An-Yu Kuo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Cycling ◽  
Solder Joints ◽  
Free Edge ◽  
Time Dependent ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
Peel Stress

AbstractA nonlinear and time dependent finite element analysis was performed on two surface mounted electronic devices subjected to thermal cycling. Constitutive equations accounting for both plasticity and creep for 37Pb/63Sn and 90Pb/10Sn solders were assumed and implemented in a finite element program ABAQUS with the aid of a user subroutine. The FE results of 37Pb/63Sn solder joints were in reasonably good agreement with the experimental data by Hall [19]. In the case of 9OPb/1OSn solder in a multilayered transistor stack, the FE results showed the existence of strong peel stress near the free edge of the joint, in addition to the anticipated shear stress. The effect of such peel stress on the crack initiation and growth as a result of thermal cycling was discussed, together with the singular behavior of both shear and peel stresses near the free edge.

A Comparative Study of the Response of Double Shearing and Hypoplastic Models

2002 ◽  
Author(s):  
Huaning Zhu ◽  
Morteza M. Mehrabadi ◽  
Mehrdad Massoudi
Keyword(s):  
Cyclic Loading ◽  
Mechanical Response ◽  
Constitutive Relations ◽  
Constitutive Models ◽  
Shear Loading ◽  
Biaxial Compression ◽  
Finite Element Program ◽  
Cyclic Shear ◽  
Hypoplastic Model ◽  
Element Program

The principal objective of this paper is to compare the mechanical response of a double shearing model with that of a hypoplastic model under biaxial compression and under cyclic shear loading. As the origins and nature of these two models are completely different, it is interesting to compare the predictions of these two models. The constitutive relations of the double shearing and the hypoplastic models are implemented in the finite element program ABACUS/Explicit. It is found that the hypoplastic and the double shearing constitutive models both show strong capability in capturing the essential behavior of granular materials. In particular, under the condition of non-cyclic loading, the stress ratio and void ratio predictions of the double shearing and the hypoplastic models are relatively close, while under the condition of cyclic loading, the predictions of these models are quite different. It is important to note that in the double shearing model employed in this comparison the shear rates on the two slip systems are assumed to be equal. Hence, the conclusions derived in this comparison pertain only to this particular double shearing model. Similarly, the hypoplasticity model considered here is that proposed by Wu, et al. [30] and the conclusions reached here pertain only to this particular hypoplasticity model.

A Flexure-Shear Coupling Fiber-Section Model for the Cyclic Behavior of R/C Rectangular Hollow Section Bridge Piers

2011 ◽  
Vol 374-377 ◽  
pp. 2009-2012
Author(s):  
Ning Li ◽  
Zhong Xian Li ◽  
Li Li Xie
Keyword(s):  
Nonlinear Behavior ◽  
Simulation Models ◽  
Constitutive Relationship ◽  
Bridge Piers ◽  
Cyclic Behavior ◽  
Thin Wall ◽  
Finite Element Program ◽  
Hollow Section ◽  
Element Program ◽  
Shear Coupling

Reinforced concrete (R/C) bridge pier with hollow section may undergo strongly nonlinear responses when subjecting severe earthquakes. The pier may perform flexure-shear coupling behavior, especially for the thin wall of the hollow section. Some simulation models accounting flexure-axial coupled effects were proposed, however, few simulation model is proposed for R/C hollow section bridge piers mainly impacted by the flexure-shear coupling. In this paper a beam-column element accounting for flexure-shear effect is presented. The mathematical theory for this element is flexibility-based formulation, and the section constructed by fibers can be treated as any kind of bi-axial materials. The cyclic soften membrane model (CSMM) constitutive relationship for plane bi-axial R/C components is used in the determination of the nonlinear behavior. Two cyclic pushover experiments were carried on scaled hollow section piers. The results deduced from the numerical model is compared with the experiment result. This fiber-based model provides sufficient accuracy and computational efficiency. The model has been implemented into the finite element program, OpenSees. And further researches will focus on the flexure-shear induced damage and collapse for bridge structures.

Friction Force and Stresses Analysis for Contact of Assembled Details

2006 ◽  
Vol 113 ◽  
pp. 334-338
Author(s):  
Z. Dreija ◽  
O. Liniņš ◽  
Fr. Sudnieks ◽  
N. Mozga
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Plastic Deformation ◽  
Friction Force ◽  
Sliding Friction ◽  
Friction Model ◽  
Contact Interface ◽  
Finite Element Program ◽  
Elastic Plastic ◽  
Element Program

The present work deals with the computation of surface stresses and deformation in the presence of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range from fully elastic through elastic-plastic to fully plastic contact interface. Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact load and areas that have strong effect on the friction force. The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is found out and its connection with plasticity index. A finite element program for determination contact analysis of the assembled details and due to details of deformation that arose a normal and tangencial stress is used.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Mechanical Property Analysis and Numerical Simulation of Honeycomb Sandwich Structure’s Core

2013 ◽  
Vol 631-632 ◽  
pp. 518-523 ◽  
Author(s):  
Xiang Li ◽  
Min You
Keyword(s):  
Numerical Simulation ◽  
Elastic Constants ◽  
Sandwich Structure ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Finite Element Program ◽  
Honeycomb Sandwich ◽  
Calculation Results ◽  
Element Program ◽  
Typical Satellite

Owing to the lack of a good theory method to obtain the accurate equivalent elastic constants of hexagon honeycomb sandwich structure’s core, the paper analyzed mechanics performance of honeycomb sandwich structure’s core and deduced equivalent elastic constants of hexagon honeycomb sandwich structure’s core considering the wall plate expansion deformation’s effect of hexagonal cell. And also a typical satellite sandwich structure was chose as an application to analyze. The commercial finite element program ANSYS was employed to evaluate the mechanics property of hexagon honeycomb core. Numerical simulation analysis and theoretical calculation results show the formulas of equivalent elastic constants is correct and also research results of the paper provide theory basis for satellite cellular sandwich structure optimization design.

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