共查询到20条相似文献,搜索用时 15 毫秒
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随着树脂复合减振板的冲压件在汽车及家电等领域的广泛应用,其冲压成形性能研究受到重视。该文从加载速度及成形件的存放时间的关系出发,研究树脂复合减振板的弯曲回弹特性,通过采用90°V形弯曲件回弹模型,针对4种不同的加载速度和工件的存放时间,对树脂复合减振板进行回弹试验。试验结果表明,在加载速度为0.5mm/s~5mm/s时,随着加载速度的增加,树脂复合减振板的回弹角逐渐减小,直到趋于稳定;无论哪种加载速度,树脂复合减振板的回弹角均随存放时间的增加而减小,直到趋于稳定。 相似文献
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Mechanical properties of galvannealed (GA) steel sheet used for automotive exposed panel and predicted failure phenomenon of its coating layer were evaluated using finite element method. V-bending test was performed to understand better the fracture of coating layer of GA steel sheet during plastic deformation. Yield strength of the coating layer was calculated by using a relative difference between hardness of coating layer measured from the nano-indentation test and that of substrate. To measure shearing strength at the interface between substrate and coating layer, shearing test with two specimens attached by an adhesive was carried out. Using the mechanical properties measured, a series of finite element analyses coupled with a failure model was performed. Results reveal that the fracture of coating layer occurs in an irregular manner at the region where compressive deformation is dominant. Meanwhile, a series of vertical cracks perpendicular to material surface are observed at the tensile stressed-region. It is found that 0.26-0.28 of local equivalent plastic strain exists at the coating and substrate at the beginning of failure. The fracture of coating layer depends on ductility of the coating layer considerably as well. 相似文献
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采用弹塑性大变形更新的Lagrange有限元方法研究了铝板 /塑料混合成型过程中铝板的成形过程和变形特点。结果表明 ,当塑料熔体压力从 30MPa增大到 5 0MPa时 ,铝板凸缘区已基本不再参与变形 ,铝板上两个板厚减薄较严重的大塑性变形区在此阶段形成。模底接触区与自由变形区交界处的大塑性变形区依次处于板料曲面内双向伸长变形和平面应变状态 ;模腔入口圆角区与自由变形区交界处的大塑性变形区由两部分构成 ,其中与模壁接触部分依次处于板料曲面内双向伸长变形、拉伸变形和平面应变状态 ,另一部分依次处于板料曲面内双向伸长变形和平面应变状态。 相似文献
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The finite element formulation for predicting strain distributions and weld line movements in the forming processes of tailored
sheet metals is developed. The material properties of the welding zone such as strength coefficient, work-hardening exponent,
and plastic anisotropic parameter are analytically obtained from those of base metals based on the tensile tests. The welding
zone is modelled with the several, narrow finite elements called by weld elements. To verify the finite element formulation
for tailored blanks, the forming processes of autobody door inner panel section and hemispherical dome are simulated. FEM
predictions are compared and showed good agreements with experimental measurements. 相似文献
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Experimental and numerical investigation of laminated steel sheet in V-bending process considering nonlinear visco-elasticity of polymer layer 总被引:1,自引:0,他引:1
Laminated steel sheet consists of two steel sheets and a polymer layer which bonds them. During forming process, mechanical properties of polymer layer significantly influence the shape of final product. In this study, a continuum model in which nonlinear visco-elasticity is taken into account has been developed for polymer layer of laminated steel sheet and implemented in a commercial finite element program by material subroutines. Lap-shear test and T-peel test have been conducted to obtain parameters of this continuum model. Two different methods are compared to establish a better method for modeling the polymer layer deformation in lap-shear test simulation. One is cohesive zone element and the other is contact method. In order to assess calculation efficiency, both explicit and implicit procedures are used to simulate lap-shear test, and T-peel test is simulated by implicit procedure to evaluate accuracy. The result indicates that cohesive element is easier to solve convergence problem and implicit procedure may save much simulation time. T-peel test data can be used to describe the normal mechanical behavior of polymer layer in an acceptable range. Finally, V-bending forming process has been studied to investigate the effect of polymer layer on the springback and final deformation shape through experiment and numerical simulation. The result indicates that the comparison between numerical simulation and experiment is in good agreement. The finite element model can accurately predict the final shape after bending and springback. 相似文献
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镀层金属板在加工过程中,由于工艺参数、模具几何参数的影响,经常会出现裂纹,并最终导致板材的断裂。以双面电沉积镍的低碳钢板为研究对象,采用基于连续介质损伤有限元模拟以及冲压成形实验相结合的方法对镀层金属板在冲压过程中的失效问题进行了研究。结果表明:随着冲压深度的增加,杯形件中的等效塑性应变与损伤值均增加,当冲压深度达到10mm时,在杯形件冲头圆角处出现断裂现象。通过冲力冲程曲线与成形件形状的比较和损伤变量分布、等效塑性应变分布以及厚度减薄的分析发现,有限元模拟结果与冲压成形的试验结果符合得较好,证明了有限元模拟的正确性。 相似文献
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为了研究用于家用轿车车身制造的镀锌钢板电阻点焊工艺,采用多元非线性回归正交组合的方法设计试验.试验将电阻点焊熔核形状参数和焊接接头抗剪强度作为考察指标,将焊接电流、电极压力、通电时间、预热电流四个参数,以及各参数之间的交互作用作为影响指标的考察因素,得到可预测熔核形状和焊接接头力学性能的四元二次回归数学模型,并通过方差分析对模型进行优化.结果表明,优化的回归数学模型可实现焊接接头熔核成形及力学性能较为准确的预测.在模型的基础上研究各参数及各交互作用对焊点质量的影响规律,从而可实现电阻点焊工艺参数的优化设计. 相似文献
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Initial investigations into coated steel sheets were conductted to verify whether sample- and batch-independent classification of surface condition can be achieved with multi-inductive data acquisition and multivariate data analysis without using a priori information. Using an ‘integrated sensor’ - a multi-inductive sensor - it is possible to obtain parameters of eddy currents, hysteresis and noise voltage with PC control. These parameters are the input values of multivariate data analysis. 相似文献
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激光微冲击成形是利用脉冲激光产生的等离子体爆轰波的冲击力效应,使超薄板材产生塑性变形的新技术。为揭示板材参数、激光参数、微凹模直径等对成形过程的影响,利用动态显式有限元法,对低碳钢箔的激光微冲击成形进行了反映率效应和尺度效应的晶粒级有限元模拟,结果表明,晶界对激光微冲击成形的影响很大,薄板的下凹变形随晶界厚度的减小而增大,二者呈近似线性关系;板材晶粒越不规则,其变形量越大;激光冲击的峰值压力是箔材变形的主要因素,随峰值压力的提高,变形量增大;单点多次冲击时,首次冲击的变形量最大,以后各次冲击的变形量逐渐减小。 相似文献
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采用ABAQUS有限元软件对电沉积镍涂层钢板的冲压成形过程进行了模拟。并用ABAQUS内置的内聚力模型来表征电沉积镍涂层钢板的界面性能。计算表明:在冲压过程中,电沉积镍涂层钢板界面法向应力在-113.765~3 MPa之间,切向应力最大为50 MPa。分析发现,在冲压过程中任意时刻凹模圆角处的界面应力最大,最后通过变换压边力、冲头与凹模间隙、摩擦系数、圆角半径分析了界面破坏的情况,研究了这些工艺参数对界面的影响,该方法以及所得结果对板料成形的生产能起到一定的指导作用。 相似文献
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轿车减振器盖用钢板的双相处理工艺研究 总被引:1,自引:0,他引:1
本文试验研究了10#钢板的双相处理工艺、组织和性能,结果表明在(α+γ)两相区不同温度加热淬火处理获得了不同(F+M)比例的双相钢钢板,其力学性能可通过调整双相处理及回火工艺来调节,用10#双相钢钢板试制成了轿车底盘零件——减振器盖。 相似文献
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Zhrgang Wang Tamotsu Nakamura Kuniaki Dohda Toshihiro Obika 《Journal of Materials Processing Technology》2003,140(1-3):514-519
This paper describes the contact situation between the die and the lubricant pre-coated steel sheet in the press-forming by using FEM simulation. The FEM simulation is carried out by supposing that the lubricant pre-coated steel sheet consists of the lubrication layer and thick galvanized layer. Both the lubrication layer and galvanized layer are assumed as rigid–plastic material. The variations in the contact situation between the die and the lubricant pre-coated steel sheet are investigated by changing the friction coefficient between the die and lubrication layer, the thickness and hardness of lubrication layer, the velocity ratio of the relative sliding velocity to pressing velocity, etc. The simulated results show that the contact area ratio is influenced largely by the average contact pressure, the velocity ratio, the thickness of lubrication layer, and friction coefficient. 相似文献