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Evaluation of complex time-dependent stress field and reduction of loss energy for viscoelastic laminated tires

粘弹性层压轮胎的复杂瞬态应力场评估和能量损失降低

基本信息

批准号：
15360060
负责人：
TAKASHI Masahisa
金额：
$ 8.45万
依托单位：
Aoyama Gakuin University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

Techniques for stress/strain analysis in viscoelastic materials give the various knowledge to design composite structures of tires and to reduce running resistance of tires. In the present research, digital holography and digital image correlation method were developed to analysis the stress/strain field in viscoelastic materials. The experimental results show that the digital holography has accuracies of 30nm in displacement measurement and of 7.5×10^<-6> in strain measurement. These accuracies are enough to measure the displacement field in viscoelastic materials. And, the experimental data obtained by digital image correlation method shows that the method can measure the full field displacement in viscoelastic materials in real time, even if the materials are subjected large deformation. These developed techniques were also applied to fracture mechanics and the authors showed that the techniques are useful to determine stress intensity factors. On the other hand, the authors developed experimental-numerical hybrid technique because it is difficult to analyze stress state in viscoelastic material only from experimental displacement data. In the developed hybrid technique, finite element model of viscoelastic object is constructed, and then, the measured experimental displacement data is inputted on the boundary of the constructed finite element model. Consequently, the stress and strain fields in the viscoelastic object are simultaneously calculated. The results show that the stress and strain fields in the viscoelastic object under non-proportional loading can be analyzed exactly by the proposed technique.

粘弹性材料的应力/应变分析技术为设计轮胎的复合材料结构和降低轮胎的行驶阻力提供了各种知识。本研究发展了数字全息术和数字图像相关法来分析粘弹性材料的应力/应变场。实验结果表明，该数字全息术的位移测量精度为30 nm，应变测量精度为7.5×10 ~ 4<-6>。这些精度足以测量粘弹性材料中的位移场。通过数字图像相关法获得的实验数据表明，该方法能够真实的实时测量粘弹性材料的全场位移，即使材料受到大变形时也能测量。这些开发的技术也适用于断裂力学和作者表明，该技术是有用的，以确定应力强度因子。另一方面，由于仅从实验位移数据难以分析粘弹性材料中的应力状态，作者发展了实验-数值混合技术。在开发的混合技术，粘弹性物体的有限元模型的构建，然后，测量的实验位移数据被输入到所构建的有限元模型的边界上。因此，在粘弹性物体的应力和应变场的同时计算。结果表明，该方法可以准确地分析非比例载荷作用下粘弹性物体的应力应变场。