Rate-dependent mechanical response of fly ash cenospheres polyurethane syntactic foams (CPSFs) with hierarchical cell structure was examined through dynamic compression tests. Quasi-static compression strength and specific energy absorption varied in the range of 9.5–29.5 MPa and 4.8–13.0 MJ/m³ within the density of 0.5–0.7 g/cm³. The thermal conductivity coefficient of CPSFs increased from 0.08 W/m/K to 0.13 W/m/K with density, while the specific heat capacity varied in a narrow range of 0.9–1.07 J/g/K. At high strain rates the strength and plateau stress of CPSFs with density of 0.6 g/cm³ increased 25%–39% and 13%–43%. The proposed foam is comparative potential in civil engineering according to its thermal insulation performance and excellent shock dissipation properties. Due to complicated microstructure, CPSFs exhibited different strain rate sensitive behaviors in the initial collapse stage and the stable collapse stage. A constitutive relation was developed to describe dynamic stress-strain response which includes the elastic stage, the initial collapse stage characterized by nonlinear stress increasing and decreasing process, the platform stage and the densification stage. The predictions shown good accordance with the experimental results in wide strain rate range.

通过动态压缩测试检查了具有分层单元结构的粉煤灰煤胞聚氨酯复合泡沫 (CPSF) 的速率相关机械响应。准静态压缩强度和比能量吸收在 9.5-29.5 MPa 和 4.8-13.0 MJ/m ^{3 的}范围内变化，密度为 0.5-0.7 g/cm ³。CPSFs 的导热系数随密度从 0.08 W/m/K 增加到 0.13 W/m/K，而比热容在 0.9-1.07 J/g/K 的狭窄范围内变化。在高应变率下，密度为 0.6 g/cm ³的 CPSF 的强度和平台应力增加了 25%–39% 和 13%–43%。根据其隔热性能和出色的减震性能，所提出的泡沫在土木工程中具有相当的潜力。由于微观结构复杂，CPSFs在初始坍塌阶段和稳定坍塌阶段表现出不同的应变速率敏感行为。建立了描述动态应力应变响应的本构关系，包括弹性阶段、以非线性应力增减过程为特征的初始坍塌阶段、平台阶段和致密化阶段。在较宽的应变率范围内，预测结果与实验结果非常吻合。