【摘要】 利用扫描电镜(SEM)对减振材料的微孔结构进行了表征;用万能材料试验机(UMTM)、动态热机械分析仪(DMA)、旋转流变仪表征了减振材料在不同条件下的力学及减振性能.研究发现:不同聚氨酯减振材料进入非线性形变区域的压缩形变大小与微孔的面积占有率相关.我们认为聚氨酯泡沫减振材料在小压缩应变下应力的缓慢增加主要是由微孔的变形引起的,随着压缩应变进一步增加,微孔的变形接近极限,此时应力的快速增加主要由聚氨酯本体的力学性能决定.聚氨酯减振材料的损耗能随着压缩应变的增加而增加,减振性能好的材料具有较大的损耗能.聚氨酯减振材料的损耗角随着压缩频率的增加而略有增加,其影响减振材料在不同使用频率下的减振和产热性能.聚氨酯减振材料的损耗角随着温度的变化而发生变化,耐寒性和耐热性好的材料,损耗角随温度平缓变化的温度范围更宽.当减振材料受到一定的负载后,材料的损耗角降低.更多还原

【Abstract】 Scanning electron microscope( SEM) was used to study the microcellular structure of the damping material. Universal material testing machine( UMTM),dynamic mechanical thermal analysis( DMA) and rotational rheometer were used to measure the mechanical properties and damping properties under different conditions. For the three different damping materials,it was observed that the value of the critical compression strain where the damping material changed to non-linear deformation regime was connected with the ratio of microcellular area versus the bulk area of cutting surface. It was inferred that the slow growth of stress for damping materials under small compression strain was contributed from the deformation of microcellular. As the compression strain was further increased,the deformation of microcellular reached its limitation,and accordingly,the rapid growth of the stress was mainly caused by the deformation of the bulk polyurethane. It was observed that the hysteresis energy of damping materials increased with the maximum compression strain was increased,and the damping material with better damping properties had bigger hysteresis energy. It was found that the loss angle of damping materials increased slightly with compression frequency,which affects the damping properties and the generated heart of the damping materials with different compression frequency. It was also observed that the loss angle of damping materials changed with temperature,and the loss angle would change slightly under wider range of temperature for the damping material with better low temperature resistance and high temperature resistance. It was also found that the damping properties of samples decreased when a bigger load was applied.更多还原