复合材料层压板低速冲击和准静态压痕损伤等效性的研究

Study on Damage Equivalence of Composite Laminates Subjected to Low-velocity Impact and Quasi-static Indentation

通过对低速冲击试验和准静态压痕试验进行对比,获得了冲击能量(准静态压痕力)与层压板损伤面积、损伤宽度和凹坑深度的三组对应关系。分析表明,损伤面积、损伤宽度和凹坑深度均可作为损伤参数来建立低速冲击和准静态压痕损伤的等效性。当冲击能量或准静态压痕力达到一定值后,三组对应关系曲线上出现拐点,两类试验的拐点相差很小,且两类试验的变化趋势相同,初步说明了用准静态压痕试验替代低速冲击试验是可行的,同时在较低冲击能量(拐点值之前)下准静态压痕力近似等于相对应的冲击能量下冲击过程的最大接触力。对两类试验过程进行分析,准静态压痕试验的初始分层载荷较冲击试验稍低,但两类试验过程中载荷的变化趋势相同,进一步说明了低速冲击试验和准静态压痕试验损伤的等效性。

Through the comparison of low-velocity impact testing and quasi-static indentation and testing,three kinds of relationship are obtained between the impact energy（or the quasi-static indentation force） damage area and dent depth.An analysis of these relationships indicates clearly that the damage area and dent depth can be chosen as the damage parameters to set up the damage relationship between drop-weight impact and quasi-static indentation.When impact energy or quasi-static indentation force is reached at the some value,then,the knee point appears in the three kinds of relationship curves,and the knee-points of the two tests are very close and the variation tendency is identical,which indicates that quasi-static indentation tests may replace low-velocity impact tests.Under the lower impact energy（before knee point）,quasi-static indentation force approximately is equal to the maximum force caused by impact process of corresponding impact energy.By analyzing the process of the two tests,the delamination onset load in the quasi-static indentation is lower than that in the low-velocity impact,but the tendency of the load variation is similar,which further indicates the damage equivalence of composite laminates subjected to low-velocity impact and quasi-static indentation tests.