PBX-1炸药的力学性能和本构关系

Compressive mechanical properties and constitutive relations of PBX-1

PBX的力学行为对其安全性有重要影响。为研究PBX-1的力学性能,以PBX-1为研究对象,进行准静态力学实验和SHPB(分离式霍普金森压杆)实验研究。结果表明,准静态压缩实验中,试样的裂纹出现在与加载方向大约成45°的最大剪应力方向。SHPB实验中,在应变率100~1 500 s^-1范围内,随着应变率的提高,PBX-1炸药的动态屈服强度、动态压缩强度和破坏应变不断提高。动态屈服强度逐渐从静态的2.77 MPa增加至16.1 MPa;压缩强度从7.46 MPa增加至16.1 MPa,破坏应变从6.23%增加到26.4%。同时,基于Z-W-T模型,建立了一种含损伤的动态黏弹性本构模型,在330~1 500 s^-1应变率范围内具有较高的精度,可以较好地描述PBX-1炸药在达到破坏前的动态力学行为。

The mechanical behavior of PBX has an important impact on its safety.In order to study the mechanical properties of PBX-1,the quasi-static mechanical experiments and SHPB(split-Hopkinson pressure bar)experiments were conducted.The results showed that the crack direction was the direction of maximum shear stress,which was about 45°to the loading direction in the quasi static compression tests.In the SHPB tests,the dynamic yield strength,dynamic compression strength and failure strain of PBX-1 explosive were continuously improved with the improvement of strain rate in the range of 100?1 500 s^-1.The dynamic yield strength gradually increased from the static 2.77 MPa to 16.1 MPa.The compression strength increased from 7.46 MPa to 16.1 MPa,and the failure strain increased from 6.23%to 26.4%.At the same time,based on the Z-W-T model,a dynamic viscoelastic constitutive model with damage was established.It has a high accuracy in the range of 330?1 500 s^-1 strain rate,and could be used to describe the dynamic mechanical behavior of PBX-1 before failure.