基于弹性理论的块体冲击力和冲击能测算

针对冲击力计算模型无法准确地将接触力与局部变形联系起来的问题,进行了块体冲击的理论计算和实验研究,以提高落石的冲击力和冲击能的计算精度,进而对防护网进行优化设计。将弹性网视作弹性膜,引入狄拉克函数划分“单向均匀拉伸区”和“双向均匀拉伸区”,通过伽辽金法推导出了落石冲击力和冲击能的计算公式,最后对施加不同预拉力的弹性网进行冲击实验。将弹性网的变形量代入上述公式计算冲击力和冲击能,分析误差产生的原因。并提出修正系数对结果进行修正,修正后的冲击力、冲击能最大误差为2.8%、3.9%。与现有的落石冲击力和冲击能测算方法相比,所提测算方法更为简化,可用于模型试验中测算落石的冲击力和冲击能,为落石防护的优化设计提供基本依据。

Research on measurement of impact force and impact energy of block based on elastic theory

Aiming at the problem that the impact force calculation model cannot accurately link the contact force with local deformation, theoretical calculation and experimental research were conducted on block impact to improve the calculation accuracy of the rockfall impact force and impact energy, and then optimize the design of the protective net. The elastic net is considered as an elastic film, and the Dirac function is introduced to divide the "unidirectional uniform tensile zone" and the "bidirectional uniform tensile zone". The calculation formulas for the impact force and energy of falling rocks are derived through the Galerkin method. Finally, impact tests were conducted on the elastic nets with different pretension force. substi-tuted the deformation of the elastic net into the above formula to calculate the impact force and impact energy and analyze the reasons for the errors. And correction coefficient was proposed to correct the results. The maximum errors of the corrected impact force and energy are 2.8% and 3.9%. Compared with the existing methods for calculating the impact force and impact energy of rockfall, the proposed calculation method is more simplified. It can be used to calculate the impact force and energy of falling rocks in model experiments, providing a basic basis for optimizing the design of falling rock protection.