爆炸冲击载荷下土壤动态本构关系的实验研究

采用拉格朗日曲面拟合实验方法，根据多道记录推算出土壤的本构关系。结果表明：土壤的应力－应变关系具有明显的滞回效应，且粘土的滞回圈比砂土大。土壤的应力－应变关系还表现出波形弥散效应，应力波形图呈双波结构，粘土尤为显著。在爆炸强冲击载荷作用下，土壤表现为具有固定组成的三相物质，其变形机理随土壤深度不同而变化。在装药量为1.3-1.5g/cm^2时，地基表层（0－20cm)具有流体弹塑性，中层（20－60cm）呈粘弹塑性，下层（大于60cm)表现为线性弹性体。

Study on Dynamically Constitutive Relation of Soils under Explosive Impact Loading

This paper outlines an experimental and computational study on dynamically constitutive relations of soils, including clay and sandy soils. High speed impact experiments were conducted with ammonium nitrate explosive No.2. The Lagrangian analysis was used for a series of stress histories. Results showed that the stress strain curves appeared obvious stagnant return phenomena, strain rate effect and waveform dissipation. These properties are well accord with the dynamic behaviour of soils. Soil showed three phase property with fixed composition under strong explosive impact loading. Various deformation characteristics were found at different depth. At explosive rate of 1 3~1 5 g/cm 2, surface layer (0~20 cm) represented fluid elastoplastic property, middle (20~60 cm) viscoplastic and deeper layer (>60 cm) linear elastic.