Press Formability of the Steel/Resin/Steel Laminates Vibration Damping Sheets

钢/树脂/钢层压减振板的冲压成型性

• 批准号: 62550497
• 负责人: ITO Koichi
• 金额: $ 1.15万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1988
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62550497/
• 关键词: Sheet Metal Forming; Formability; Sandwich Sheet; Vibration Damping Sheet dVisco-Plasticity; Limit Strain; Deep Drawing; 樹脂複合材料; 粘弾性; 振動減衰

Effects of the shear flow stress of resin core on the press formability of steel/resin/steel laminates vibration damping sheets were investigated. First, for several types of sheets with different core materials, conventional sheet metal formability tests, i.e. the simple tension test, Swift cup test and the hole expansion test, were performed. It mede clear that higher shear flow stress of the core resin gives more excellent press formability, both for wrinkling and fracture resistivity. The limit strain ,at which the skin steel sheet breaks, increased for high shear flow stress of resin core. Because the shear flow stress constrained the development of strain of the outer skin layer in the localized zone. M-K model,which had been proposed by Marciniak and Kczinski,was modified to predict the limit strain of the three layers sandwich sheet under uniform biaxial plane stress states. Results of numerical calculation gives the remarkable influence off the value of shear flow stress and elastic rigidity on the limit strain.Next, double-bent phenomenon in the V-type bending process was analyzed using J2-deformation theory and the results of numerical analysis make clear some effects of shear flow stress of the resin core on double-bent phenomenon. It could determine the forming condition that ensure to perform no double-bent V-bending operation. Finally, in order to decide the visco-elastic-plastic properties of resins under simple shear, we tried to construct the torsion testing machine for the sandwiched ring specimen with resin core. Trial machine is able to torsion test with any specified path of shear strain rate. For several types of resin, workhadening rules and strain rate sensitivities are decided by the test using the trial testing machine.

研究了树脂芯剪切流动应力对钢/树脂/钢层压板冲压成形性能的影响。首先，针对几种不同芯材的板材，进行了常规的板料成形性试验，即简单拉伸试验、斯威夫特杯试验和扩孔试验。结果表明，芯树脂的剪切流动应力越大，其抗皱性和抗裂性越好。树脂芯的剪切流动应力越高，表层钢板断裂的极限应变越大。这是因为剪切流动应力制约了局域区表层应变的发展。对Marciniak和Kczinski提出的M-K模型进行了修正，使之能够预测三层夹层板在均匀双向平面应力状态下的极限应变。数值计算结果表明，剪切流动应力和弹性刚度的大小对极限应变有显著影响。其次，利用J2变形理论对V型弯曲过程中的双弯现象进行了分析，数值分析结果明确了树脂芯剪切流动应力对双弯现象的影响。它可以确定成形条件，确保不进行双弯V弯操作。最后，为了确定树脂在简单剪切下的粘弹塑性性能，我们尝试搭建了带树脂芯的夹层环状试件的扭转试验机。试验机能够在任何指定的剪切应变率路径下进行扭转试验。对于几种类型的树脂，用试验机进行的试验确定了加工硬化规则和应变率灵敏度。