一、问题的提出吊钩是起重设备的重要零件之一,国内外过去计算吊钩强度均采用弹性曲梁理论。对于机动的吊钩,安全系数通常规定:轻级和中级工作制不小于2.0,重级和超重级工作制不小于2.25[1]。许用应力规定,苏联对于20号钢,手动的[σ]=1450～1650公斤/厘米~2,机动的[σ]=1250～1500公斤/厘米~2[2];日本对吊钩安全系数规定:电动的为2,手动的为1.5[6]。国内在机动的方面沿用苏联的规定,对手动起重设备还没有统一的规范。这种计算方 First, the problem raised Hook is one of the important parts of lifting equipment, both at home and abroad to calculate the strength of the hook are used elastic curved beam theory. For maneuvering hooks, the safety factor usually stipulates that the light and mid-level work system is not less than 2.0 and the heavy and overweight work system is not less than 2.25 [1]. Allowable stress regulations, the Soviet Union for 20 steel, manual [σ] = 1450 ~ 1650 kg / cm ~ 2, mobility of [σ] = 1250 ~ 1500 kg / cm ~ 2 [2]; Japan on the hook safety factor Provisions: electric 2, manual for 1.5 [6]. In terms of maneuvering, the Soviet Union adopted the provisions of the manual lifting equipment, there is no uniform norms. This calculation side