高能发射药在高速冲击下屈服强度的分析方法刘计划

为了研究高能发射药在高速冲击下屈服强度的分析方法,利用落锤试验机进行常温(20℃)和低温(-40℃)下DAGR125发射药的冲击试验,得到不同冲击速度下发射药轴向应力的演化规律.在此过程中,结合高速摄像技术,获得冲击过程中发射药表面的灰度图像,通过数字图像相关方法得到发射药表面变形,从而建立高能发射药在冲击载荷作用下的应力应变曲线.随后,利用3种分析方法(分别为初始拐点法、切线法及二次导数法)获得了发射药在高速冲击下的屈服强度.经过对比分析发现,常温20℃下DAGR125屈服强度的有效分析方法为初始拐点法,而切线法对低温-40℃下DAGR125发射药屈服强度的确定适用性更好.

Analysis Methods of the Yield Strength of High-Energy Gun Propellant under High-Speed Impact

In this paper, analysis method of the yield strength of high-energy gun propellant is studied. The impact tests of DAGR125 gun propellants were carried out using drop hammer impact test machine, and the evolution of the axial stress was obtained under different impact velocity. In the process, combining with high-speed photography technology, gray images of the surfaces of gun propellants were gained. By digital image correlation method, the surface deformation was determined. So the stress-strain curves can be established. Then, three analysis methods (initial point of inflexion method, tangent method and second derivative method) were used to calculate the yield strengths of DAGR125 gun propellants. Based on comparative analysis, it is found that the effective analysis method of yield strength of DAGR125 gun propellant at room temperature is initial point of inflexion method, and tangent method has good applicability for the analysis of yield strength of DAGR125 gun propellant at low temperature.