试样位置和能量校正对仪器化冲击结果的影响

Influence of Specimen Position and Energy Correction on Instrumented Impact Tests

仪器化冲击是高分子材料断裂行为研究中的一种重要方法。针对试验时试样的位置和能量校正对仪器化冲击最大载荷和冲击能量的影响进行了研究。发现试样位置的偏移对仪器化冲击测量到的载荷大小具有显著影响,当横向偏移2 mm时,冲击最大载荷上升了约4%,但是当纵向偏移2 mm时,最大冲击载荷下降了约30%。建议试样纵向位置应精确至±0.2 mm范围。对几种韧性不同材料的位移校正功进行了计算,发现校正功在冲击能量中所占比例都在10%以上,与材料的韧性没有直接关系,但在分析和对比中不能忽略。计算了PE100-RC试样的动能和惯性峰能量,发现其占冲击能量的比例不到1%,对材料断裂性能的测量影响较小。

Instrumented impact test was an important method to assess the facture behavior of polymer. The influence of specimen position and energy correction on maximum impact force and impact energy from instrumented impact tests was investigated. It was found that the maximum impact forces was significantly affected by the specimen position offset. The maximum force increased by 4% , when the lateral offset was 2 mm, but when the vertical offset was 2 ram, the maximum force dropped by 30%. It was recommended that the vertical position of specimen should be accurate to ±0.2 mm of the center of percussion. The correction energies of tire displacements of several materials with difterent fracture toughness were calculated. It was found that the corrections accounted for more than 10% of the overall energies and were not directly correlated to the fracture toughness. The corrections should not be neglected in the analysis and comparison. The energy of kinetic and inertial contribution for PE100-RC specimen was calculated, it was found that the value was less than 1% of the overall energies, and the influences of kinetic energy and inertial loads were less pronounced.