【摘要】 以球形圆柱杆-方板为试验对象,进行面外接触碰撞试验。基于数字图像相关方法(DIC)搭建了应用于柔性体低速碰撞试验的三维高速摄影系统,通过对系统关键参数的设定,测量得到柔性体全场应变响应,并同应变片与数值仿真结果进行对比。结果表明,三维系统避免了二维系统受离面位移影响的弊端,能够准确测量柔性体全场位移、速度和应变响应。进行对心正碰试验得到柔性体碰撞过程和全场应变分布特征,X,Y方向应变呈"花生形";主应变呈"同心圆形";剪切应变呈"四纺锤形";在低速碰撞情况下,碰撞点最大主应变与碰撞速度呈二次幂关系。更多还原

【Abstract】 Here, based on the digital image correlation method, a 3-D high-speed videography system was constructed for flexible body lowspeed impact tests. A spherical cylindrical rod-square plate system was taken as the test object and out-of-plane contact impact tests were conducted. By settingthe system’s key parameters, the flexible body’s wholefield strain responses were measured and compared withthe results of strain gauge measurement and numerical simulation. Results showedthata 3-D system avoids drawbacks of a 2-D system being easy to be affected byout-of-plane displacements, and it can be used to accurately measure a flexible body’s wholefield displacement, velocity and strain response.2 bodies’ central normal impact tests were conducted to obtain flexible bodies’ impact process and whole field strain distribution features. It was shown that their strains in X and Y directions reveal the shape of "peanut",their principal strain fieldsreveal the shape of "concentric circle"; their shear strain fieldsreveal the shape of "four-spindle"; in the case of low-speed collision,the maximum principal strain at the collision point and impact velocity reveals a secondary power relation.更多还原