Authors: Jong Woong Kim, Sun Kyu Park, Seung Boo Jung
Abstract: Ball shear test was investigated in terms of effects of important test parameters, i.e. shear height and shear speed, with an experimental and non-linear finite element analysis for evaluating the solder joint integrity of area array packages. A Pb-free solder composition was examined in this work: Sn-3Ag-6Bi-2In. The substrate was a common SMD (Solder Mask Defined) type with solder bond pad openings of 460㎛ in diameter. It could be observed that increasing shear height, at fixed shear
speed, has the effect of decreasing shear force, while the shear force increased with increasing shear speed at fixed shear height. Too high shear height could cause some bad effects on the test results such as unexpected high standard deviation values or shear tip sliding from the solder ball surface. The low shear height conditions were favorable for screening the type of brittle interfacial failures or the degraded layers in the interfaces.
851
Authors: Yin Fang Jiang, Lei Fang, Zhi Fei Li, Zhen Zhou Tang
Abstract: As a new lightweight material and new technique,Tailor Rolled Blanks has a good prospect in energy-saving environmental protection and the future development of the automobile industry, formability window of Tailor Rolled Blanks at blank-holder force has important practical significance. Based on the research of a square box TRB, the paper proposes a theory of TRB’ formability window, also with the usage of an ABACUS finite element software to simulate the TRB sheet in the course of the critical wrinkling BHF curve and critical fracture BHF curve, to establish TRB formability window under the condition of blank holder force. The results not only show that the square box of TRB has the security zone in the deep drawing process, but also has got the wrinkling and fracture areas of the square box.
488
Authors: Chang Long Liu, Da Pei Tang
Abstract: Thermal residual stress in diamond film deposited onto Mo substrate was simulated and analyzed comprehensively by using the finite element method on condition that the substrate’s plasticity was considered. The contour plots of the stresses were described. Moreover, the effect of the film’s thickness on thermal residual stress was investigated. The results show that every stress component in the film has the remarkable stress concentration at the intersection of the interface and the side of the film. The location of maximum tensile principal stress in the film is at the upward face or side face of the film or the interface. The magnitude of maximum tensile principal stress increases when the film becomes thicker. These conclusions are useful to the proper choice of the film’s thickness and the effective control of the stresses during preparation of diamond film.
1199
Authors: Ai Rong Zhang, Xiao Liu
Abstract: Due to the dependence of the sample data for a probabilistic reliability model and the fuzzy model, the interval model was used to describe the uncertain parameters through which a new measure of non-probabilistic reliability was established. Studying the model with the non-probabilistic theory, a new measure of non-probabilistic reliability was established which was the minimum distance between the failure region and the total region constructed by all uncertain variables. This kind of measure not only is consistent with the criterion of the non-probabilistic robust reliability, but also has a clearer meaning. The validity and the feasibility were proved through a computational example.
1908
Authors: Hui Hui Zhao, Wen Fang Zhang
Abstract: The application of ABAQUS finite element software non-linear finite element analysis of brick masonry walls with structural column. Build three brick masonry wall models, and analysis of the damage form of the wall under different vertical compressive stress and horizontal force. Thus the analysis result compared with the calculation result of the relevant specification formula, in order to get validate compression influence of masonry aseismic walls. It turned out that different vertical compressive stress effect the shear capacity, and failure mode of brick masonry wall structure with a structural column.
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