考虑天气影响的防鸟刺受力分析及针刺选择

Force Analysis and Needle Selection of Anti-bird Thorns Considering the Influence of Weather

通过分析针刺受力来源,覆冰、大风天气对防鸟刺针刺受力的影响,认为针刺选择更应关注的是屈服强度和屈强比(屈服强度与拉伸强度比值),屈服强度更能适应外界天气对针刺的影响。同时根据不锈钢针刺在大风下的仿真结果可知,由于不锈钢屈服强度较低,规范中要求的针刺直径、长度下在35 m/s的风速下,只有直径3 mm、长度500 mm的针刺不会发生屈服,因此不建议使用不锈钢作为防鸟刺针刺材料。根据针刺覆冰后的仿真结果,覆冰厚度大于15 mm时规范中推荐的直径、长度的针刺均会发生屈服,所以在覆冰厚度大于15 mm的地区不再建议使用防鸟刺,可选用防鸟针板或其他防鸟设施。

Through the analysis of the source of acupuncture force and the influence of ice-covered and windy weather on force of anti-bird needles,it is believed that the selection of acupuncture should pay more attention to yield strength and yield ratio(the ratio of yield strength to tensile strength).Yield strength is more adaptable to the influence of external weather on acupuncture.Furthermore,according to simulation results of stainless steel needle punching under strong wind,it can be seen that due to the low yield strength of stainless steel,only the needle punches with a diameter of 3 mm and a length of 500 mm will not yield under the wind speed of 35 m/s required in the standard.Thereby stainless steel is not recommended as a bird sting needle stick material.According to the simulation results after needle punching with ice coating,when the thickness of ice coating is greater than 15 mm,anti-bird thorns with diameters and lengths of needle punches recommended in the standard will all yield,and anti-bird pin boards or other anti-bird facilities can then be alternatives.