冲击位置对半刚性防护网失效能量的影响研究

Effect of Impact Position on Failure Energy of Semi-rigid Protection Barriers

摘要:

针对目前半刚性落石防护网的失效能量与冲击位置之间的关系缺乏确切研究的现状,采用LS-DYNA软件建立了半刚性防护网的有限元模型,研究了不同冲击位置处防护网的失效能量,得到了钢绞线和钢柱的耗能规律,分析了各种冲击条件下防护网的破坏模式。研究表明:钢柱和钢绞线是主要的耗能构件,摩擦和阻尼耗能占比不大。落石冲击中跨跨中时,防护网的失效能量大于冲击边跨时的失效能量;落石冲击中跨跨中且纵向位置较高时,防护网的失效能量最大,落石冲击中柱底部时防护网的失效能量最小;落石冲击中跨跨中和钢柱上时,钢柱容易破坏;冲击边跨跨中底部时边柱容易破坏,冲击其他纵向位置较低时,边柱也容易破坏;冲击其他纵向位置较高时,钢绞线容易断裂。

Abstract:

In view of the current situation that the relationship between the failure energy of semi-rigid rockfall protection barriers and impact positions has not been accurately studied, LS-DYNA was used to establish a finite element model of semi-rigid protection barriers. The failure energy of the protection barriers at different impact positions was studied, and the energy dissipation laws of steel strands and steel columns were obtained. The damage modes of the protection barriers under various impact conditions were analyzed. Research shows that steel columns and steel strands are the main energy-dissipating components, and friction and damping account for a small proportion of energy consumption. When the rockfall impacts the center of mid-span, the failure energy of the protection barriers is greater than that when impacting the side span; when the rockfall impacts the center of mid-span and at a high longitudinal position, the failure energy is the maximum, and when the rockfall impacts at the bottom of the center column, the failure energy is the minimum. The steel columns are easily damaged when rockfall impacts the center of mid-span and the steel columns; the side columns are easily damaged when the rockfall impacts the bottom of the side spans or other low longitudinal positions; the steel strands break easily when the rockfall impacts other high longitudinal positions.