A Finite-Element and Experimental Analysis of Stress Distribution in Various Shear Tests for Solder Joints

1998 ◽  
Vol 120 (1) ◽  
pp. 106-113 ◽  
Author(s):  
T. Reinikainen ◽  
M. Poech ◽  
M. Krumm ◽  
J. Kivilahti
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Low Cycle Fatigue ◽  
Material Model ◽  
Lap Joints ◽  
Optical Measurements ◽  
Nonlinear Material ◽  
Lap Joint ◽  
The Finite Element Method ◽  
Shear Tests

Solder alloys are commonly tested with shear tests to study their mechanical properties or low-cycle fatigue performance. In this work, the suitability of various shear tests for quantitative solder-joint testing is investigated by means of the finite element method. The stress state and stress distribution in the following well known geometries are studied: the double-lap test, the ring and plug test, the losipescu test, and two single-lap tests. A new test geometry, the grooved-lap test, is introduced and compared to the conventional tests. The results of simulations with an elastic material model in plane-strain indicate that considerable differences in the purity of the state of shear (rε = −ε1/ε3) as well as in the stress distribution in the joint exist among the shear tests. However, simulations with a nonlinear material model show that stress inhomogenities are smoothed by the plastic and creep deformation occurring in the joint. Optical measurements of the deformation of real single-lap and grooved-lap joints show that the single-lap joint rotates slightly during creep, whereas in the grooved-lap joint no rotation can be detected. This confirms the simulation results that in the single-lap test the initially nonuniform stress distribution changes during creep, and in the grooved-lap test the uniform stress distribution remains constant through the test.

Numerical Analysis of the Stress in Joggle Double Lap Joint

2012 ◽  
Vol 511 ◽  
pp. 150-153
Author(s):  
Xiao Ling Zheng ◽  
Ling Wu ◽  
Min You ◽  
Kai Liu ◽  
Cun Jun Chen
Keyword(s):  
Stress Distribution ◽  
Equivalent Stress ◽  
Peak Stress ◽  
Middle Part ◽  
Lap Joints ◽  
Lap Joint ◽  
The Finite Element Method ◽  
Adhesively Bonded ◽  
Von Mises Equivalent Stress ◽  
Von Mises

Both normal and joggle double lap joints were numerical analyzed to get the stress distribution in mid-bondline and in adherends near the interface using the finite element method (FEM). The results from the numerical simulation show that nearly all the peak values of the stress components as well as the von Mises equivalent stress distributed in both mid-bondline and adherend near the interface of the adhesively bonded joggle double lap joint are significantly decreased to the normal one. It was pointed out that the load bearing capacity of the joggle double lap joint may be higher than that of the double lap joint for its decrease of peak stress, much evenly stress distribution in the middle part of the overlap zone so that more load can be subjected by the joggle double lap joint.

Effect of Interference on the Mechanics of Load Transfer in Aircraft Fuselage Lap Joints

2006 ◽  
Vol 129 (3) ◽  
pp. 356-366 ◽  
Author(s):  
Amarendra Atre ◽  
W. S. Johnson
Keyword(s):  
Finite Element ◽  
Stress State ◽  
Stress Distribution ◽  
Fatigue Damage ◽  
Structural Integrity ◽  
Crack Nucleation ◽  
Process Variations ◽  
Lap Joints ◽  
Multiaxial Fatigue ◽  
Lap Joint

Much of the fatigue damage in aircraft structures can be linked to the stress concentration arising at the rivet/skin interface in fuselage lap-joints. Fatigue damage can degrade the strength of the structure and reduce structural integrity. The stress distribution around the rivet holes, which depends on several loading conditions, is therefore of prime importance. Critical manufacturing process variations must be taken into account to observe the effect on local stresses at the hole. This paper presents three-dimensional (3D) nonlinear finite element analyses to investigate the stress state at rivet holes in fuselage lap joints. Initially, a 3D single rivet model of the riveting process was developed to characterize the unsymmetric residual stress distribution resulting from rivet installation. Then a global three-rivet model of the fuselage lap-joint, which takes into account the residual stresses from rivet installation and fuselage pressurization, was analyzed and compared to observations available from teardown inspection. The models were then implemented to observe the effects of rivet interference, sealant, and drill shavings on the stress state. A multiaxial fatigue criterion was implemented to predict cycles to crack nucleation for the modeled parameters. The effect of underdriven rivets and sealant were observed to be the most critical on the stress state of the fuselage splice. Excellent comparison with the damage characterization of the fuselage lap-joint provides validation to the finite element model.

Application of the Finite Element Method in Screening of Body Turn up Heights for Radial Truck Tires

2001 ◽  
Vol 29 (3) ◽  
pp. 186-196 ◽  
Author(s):  
X. Yan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Material Model ◽  
The Finite Element Method ◽  
Truck Tires ◽  
Contact Constraint ◽  
Nonlinear Mechanical ◽  
Critical Regions ◽  
Constraint Method ◽  
Element Method

Abstract A method is described to predict relative body turn up endurance of radial truck tires using the finite element method. The elastomers in the tire were simulated by incompressible elements for which the nonlinear mechanical properties were described by the Mooney-Rivlin model. The belt, carcass, and bead were modeled by an equivalent orthotropic material model. The contact constraint of a radial tire structure with a flat foundation and rigid rim was treated using the variable constraint method. Three groups of tires with different body turn up heights under inflation and static footprint loading were analyzed by using the finite element method. Based on the detail analysis for stress analysis parameters in the critical regions in the tires, the relative body turn up edge endurance was predicted.

Stress in Bonded Adherends for Single Lap Joints

1996 ◽  
Vol 12 (03) ◽  
pp. 167-171
Author(s):  
G. Bezine ◽  
A. Roy ◽  
A. Vinet
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Numerical Model ◽  
Stress Distribution ◽  
Normal Stress ◽  
Lap Joints ◽  
Axial Loads ◽  
Normal Stress Distribution ◽  
Single Lap Joints ◽  
Element Technique

A finite-element technique is used to predict the shear stress and normal stress distribution in adherends for polycarbonate/polycarbonate single lap joints subjected to axial loads. Numerical and photoelastic results are compared so that a validation of the numerical model is obtained. The influences on stresses of the overlap length and the shape of the adherends are studied.

scholarly journals Multi-scale Method for the Crack Problem in Microstructural Materials

2010 ◽  
Vol 10 (1) ◽  
pp. 69-86 ◽  
Author(s):  
R. H. W. Hoppe ◽  
S.I. Petrova
Keyword(s):  
Finite Element ◽  
Crack Problem ◽  
Material Model ◽  
Superposition Method ◽  
The Finite Element Method ◽  
Multi Scale ◽  
Microscopic Models ◽  
Modeling Strategy ◽  
Porous Microstructures ◽  
Global And Local

AbstractThe paper deals with the numerical computation of a crack problem posed on microstructural heterogeneous materials containing multiple phases in the microstructure. The failure of such materials is a natural multi-scale effect since cracks typically nucleate in regions of defects on the microscopic scale. The modeling strategy for solving the crack problem concerns simultaneously the macroscopic and microscopic models. Our approach is based on an efficient combination of the homogenization technique and the mesh superposition method (s-version of the finite element method). The homogenized model relies on a double-scale asymptotic expansion of the displacement field. The mesh superposition method uses two independent (global and local) finite element meshes and the concept of superposing the local mesh arbitrarily on the global continuous mesh. The crack is treated by the local mesh and the homogenized material model is considered on the global mesh. Numerical experiments for problems on biomorphic microcellular ceramic templates with porous microstructures of different materials constituents are presented.

Nonlinear Behaviour of Concrete Foundation Slab

2016 ◽  
Vol 821 ◽  
pp. 495-502
Author(s):  
Josef Fiedler ◽  
Tomáš Koudelka
Keyword(s):  
Finite Element Method ◽  
Concrete Slab ◽  
Material Model ◽  
Nonlinear Material ◽  
Nonlinear Behaviour ◽  
Plastic Yielding ◽  
The Finite Element Method ◽  
Foundation Slab ◽  
Subsoil Model ◽  
Concrete Computation

A layered model is used for nonlinear analysis of a foundation concrete slab. Calculation is performed using interaction with elastic Winkler-Pasternak subsoil model and considering plastic yielding of slab layers. Two Drucker-Prager yield criterions define a nonlinear material model for concrete. Computation is done by the SIFEL solver using the Finite Element Method.

Improvements for a Hydraulic Excavator's Boom

2014 ◽  
Vol 490-491 ◽  
pp. 510-513
Author(s):  
Sheng Bin Wu ◽  
Xiao Bao Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
High Stress ◽  
The Finite Element Method ◽  
Element Method ◽  
Concentration Phenomenon

Focus on stress concentration and high stress area, four improvements were put forward through analyzed a hydraulic excavator's boom with the finite element method under the bucket digging condition. Compared the stress distribution graph, the results show that these schemes can improve the stress concentration phenomenon and the high stress distribution areas. The practices demonstrated the effectiveness to reduce the invalidation rate of hydraulic excavator's boom.

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