锤头曲率半径对RC梁抗冲击性能影响

Influence of hammer geometry on impactperformance of RC beams

为了研究锤头曲率半径对钢筋混凝土(RC)梁的抗冲击性能影响,对Kazunori Fujikake等人完成的RC梁冲击试验建立精细化有限元模型,并与试验结果进行对比验证有限元模型的准确性。并基于已验证的有限元模型开展拓展参数分析。有限元分析表明:所建立的精细化有限元模型能够较好地模拟混凝土梁在冲击荷载作用下的动力响应;随着锤头曲率半径的提高,落锤与RC梁之间接触刚度提高;冲击加载速率越高,冲击力峰值越大;在不同的落锤初始倾斜角下,当锤头具有一定曲率时,冲击力峰值更加稳定;随着锤头曲率半径的提高,冲击力峰值随着冲击速度增长更快;锤头曲率半径越小,局部破坏越明显。

In order to study the influence of hammer curvature radius on the resistance of RC beams under impact load,high-fidelity finite element models were built based on the impact test of RC beams conducted by Kazunori Fujikake et al.The accuracy of the finite element model was verified by comparing it with the experimental results.The verified finite element model was utilized to study the influence of different hammer curvature of drop weight on the dynamic response of RC beam under impact load.The results indicate that:1)the FE model can well simulate the dynamic response of RC beam under impact load;2)the contact stiffness between the drop hammer and the RC beam rises with the increase of the curvature radius of the hammer;3)the higher the impact loading rate,the greater the peak value of the impact force;4)when the curvature of the hammer is not zero,the peak value of impact force measured by the drop hammer is more stable at different initial inclination angles of the drop hammer;5)with the increase of the radius of curvature of hammer head,the peak value of impact force increases faster with the impact velocity;6)the smaller the radius of curvature of hammer head,the more obvious the local damage.