光滑帽子动态本构模型验证及应用研究

Validation and application of continuous surface cap model used as the dynamic constitutive model of soil

通过弹丸侵彻模型试验及数值方法论证光滑帽子模型可较好模拟一定范围内冲击荷载作用下土体动态力学响应。在此基础上分析不同本构模型、数值算法对计算结果影响。分析表明,光滑帽子模型能克服在较的静水压力及低速下数值计算不稳定,与土壤、泡沫模型及Drucker-Prager模型相比,基本上能反映土体力学性能,计算结果更合理;用MM-ALE算法模拟弹丸侵彻试验能克服网格畸变所致数值计算困难,计算精度能得到保证,计算结果与事实相符。该结果对研究武器触地侵彻过程中弹头强度、刚度、炸药安定性及战斗部入地后的爆炸破坏效应具有重要意义。

For simulating the dynamic response of soil under a certain range of impact load caused by projectile penetration,continuous surface cap model was proposed to be used as the dynamic constitutire model of soil. Through model test and numerical simulation,the feasibility and advautages of the model were validated. The influences of different constitutive models and numerical algorithms on penetration depth were analysed. The results show that in the calculation using continuous surface cap model,numerical instability can be overcome in the case of low hydrostatic pressure and low penetrating velocity. Compared with the soil and foam model and the Drucker-Prager model,the continuous surface cap model can more closely reftect the mechanical properties of soil,so,the result will be more resonable. In the simulation of projectile penetration,multi material arbitrary Lagrangian-Eulian（ MM-ALE） algorithm was intrduced and it is shown that with MM-ALE algorithm,the mesh distortion and numerical difficulties can be conquered,the calculation accuracy can be thus guaranteed,so that more credible results can be achieved. The results are helpful to study the strength and rigidity of warhead,the stability of explosive during the penetration of projectile and the effect of blast damage after the projectile penetrating into the ground.