为了改进泡沫铝的动态吸能性能,将聚氨酯填充到开孔泡沫铝中制备成复合材料。通过霍普金森杆(SHPB)冲击实验,研究包含相对密度、应变、应变率和聚氨酯含量等影响因素的聚氨酯泡沫铝材料的动力学性能,并建立了动态本构模型。实验结果表明,聚氨酯泡沫铝的动态弹性模量与相对密度无关,屈服强度和流变应力与应变率和泡沫铝的相对密度成正比;聚氨酯泡沫铝的屈服强度与泡沫聚氨酯质量增加近似呈线性关系。所建立的动态本构模型在相对密度和应变率在一定的变化范围内与实验数据吻合较好。
A new kind of composite energy absorption material was made by filling the holes of opencell aluminum foam with polyurethane. Split Hopkinson pressure bar impact experiments were per formed to evaluate the dynamic mechanical property of the polyurethane foam aluminum complex material. Based on the test results, we analyzed the mechanical behaviors of the material through influencing factors including relative density, strain, strain rate and content of polyurethane. Then the dynamic constitutive model was established. It was shown that: the dynamic modulus of elasticity of the composite material is independent of the relative density; the yield strength and the flow stress of the composite material varies directly with the strain rate and the relative density; the yield strength of the composite material varies directly with the mass of the polyurethane foam. It was proved that in definite ranges of relative density and strain rate, the curves of constitutive model fit well with the curves of experimental data. So the dynamic constitutive model has some reference value to engineering applications.