Hugoniot实验的粒子速度测量不确定度分析

Evaluation for Uncertainty of Particle Velocity in Hugoniot Measurements

不确定度评定是Hugoniot实验的一项重要工作,针对飞片撞击法和对比法两类主要Hugoniot实验进行了粒子速度的测量不确定度分析。根据直接测量量和间接输入量及其不确定度,用不确定度传递律表述了粒子速度的不确定度,并给出了冲击压强(p)、压缩密度(ρ)和压缩比容(v)的评定方法。对于样品和基板为不同材料的非对称碰撞及对比法实验,不确定度评定除A类评定外还应包括B类评定,应考虑用Hugoniot镜像线近似二次冲击绝热线或卸载线而导入的不确定度。在Hugoniot实验中应尽量避免涉及B类评定的其它因素,如同种材料初始密度的显著差异、飞片击靶前的温升等情况。

Uncertainty of particle velocity (u) was systemically analyzed in terms of the general guide to uncertainty evaluation, focusing on two principal types of Hugoniot measurements-flyerplate-impact experiment and relative measurement. The uncertainties of the shock velocity (D), shock pressure (p), compressional density (ρ) and compressional specific volume (v) were also formulated in detail based on the law of propagation of uncertainty. For both asymmetric impact (different kinds of sample and driver) and relative measurement, the uncertainty resulted from the approximation of double-shock Hugoniot or release to the mirror reflection of the principal Hugoniot should be taken into account as Type B evaluation of uncertainty. The situations, such as the obvious difference of the same kind of materials, the temperature rise of the flyer prior to impact and so on, should be avoided in Hugoniot experiments.