低速冲击下C型冷弯薄壁钢构件动力响应分析

为了研究C型冷弯薄壁钢构件在横向冲击荷载作用下的动力性能，本文选用两组共12个冷弯薄壁槽钢梁构件进行冲击试验，并将试验构件的变形模式和试验测得的位移极值与ANSYS/LS-DYNA有限元模拟所得的结果进行对比分析，结果表明：两者的构件变形模式相似，位移极值差值均在8.0%以内，表明ANSYS/LS-DYNA有限元模型能够准确有效的模拟该构件的动力响应结果。采用该数值模型依次分析了不同冲击参数（密度、速度和角度）对C型冷弯薄壁槽钢梁构件的变形模式和动力性能的影响。结果表明：当冲击物密度在2000-8000kg/m3内以2000 kg/m3的增量增大时，构件冲击力最大增加25.5%，竖向位移最大值为20.30mm，应变能稳定值所占峰值的比例基本保持在60.0%左右；当冲击物速度在3-9m/s内以3m/s的增量增大时，构件冲击力最大增幅为79.1%，竖向位移最大值为26.78mm，应变能稳定值所占峰值的比例基本保持在60.0%左右；当冲击物冲击角度由30°增加到90°，构件冲击力最大增幅为41.4%，竖向位移最大值为20.09mm，应变能稳定值所占峰值的比例在60.0%-70.0%之间。因此，冲击物密度、速度与冲击角度的改变，对构件的变形和破坏程度均有影响，但冲击速度的改变对构件变形程度的影响最为显著。

Dynamic Response Analysis of C-section Cold-formed Thin-walled Steel Members Under Low-velocity Impact

In order to study the dynamic performance of C-type cold-formed thin-walled steel members?under transverse impact loading, in this paper, two groups of 12 members were selected for impact test. The deformation modes and displacement extremum of the test members were compared with the results of ANSYS/LS-DYNA finite element simulation and the results showed that the deformation modes of the two members were similar, and the difference of displacement extremum was less than 8.0%, which indicated that ANSYS/LS-DYNA finite element model could accurately and effectively simulate the dynamic response of the member. Then, the numerical model was used to analyze the influence of different impact parameters (density, velocity and angle) on the deformation mode and dynamic performance of C-type cold-formed thin-walled steel members successively. The results showed that the maximum impact force of members increased by 25.5%, the maximum vertical displacement was 20.30mm, and the proportion of stable strain energy in the peak value was basically maintained at 60.0% when the density of impactor increased by 2000 kg/m3 in the range of 2000-8000kg/m3; when the velocity of the impactor increased by 3m/s in the range of 3-9m/s, the maximum impact force of the member increased by 79.1%, the maximum vertical displacement was 26.78mm, and the proportion of the stable strain energy in the peak value basically remained at 60.0%; when the impact angle of the impactor increased from 30° to 90°, the maximum amplification of impact force was 41.4%, the maximum vertical displacement was 20.09mm, and the proportion of stable strain energy in the peak value was between 60.0% and 70.0%. Eventually, the deformation and degree of damage of the member are affected by the change of impactor (object) density, velocity and impact angle, and the impact velocity has the most outstanding influence on the deformation of the member.