【摘要】 从分析霍布金逊压杆测试中试样变形应力、入射应力、反射应力和透射应力的相互关系入手,获得满足试样恒应变率变形所需的加载条件,即只有当加载应力和试样的变形应力具有相同的变化规律时,试样变形才处于恒应变率状态。试验结果表明,整形器法和异形冲头法都能在一定程度上实现试样的恒应变率测试,双试样法实际是整形器法的一个特例。整形器法更适合于理想弹脆性岩类的测试,异形冲头法对具有幂函数型本构曲线岩类和未知本构特征材料的测试有利,并且可重复性好。能产生半正弦波的异形冲头法可减小波形弥散对测试结果的影响。更多还原

【Abstract】 The relationships among specimen stress,incident stress,reflected stress and transmitted stress were analyzed;and the loading condition for specimen deformation at constant strain rate was found out,i. e.,only when the loading stress and deformation stress in specimen have the same changing pattern,the specimen deforms at a constant strain rate. The tests show that constant strain rate of specimen can be achieved by pulse shaper method and special shape striker method. Double specimen method is actually a special case of pulse shaper method. Pulse shaper method is favorable for tests of perfect elastic brittle material. And special shape striker method is useful for the split Hopkinson pressure bar(SHPB) tests of materials with power function constitutive relation or materials with no foregone constitutive information. Special shape striker method has more repeatability than pulse shaper method. Special shape striker method with half-sine incident wave can reduce the influences caused by wave dispersion.更多还原