蒙皮加筋圆柱壳弯曲频率的三种计算模型

研究了加筋圆柱壳弯曲刚度的面积等效和惯性矩等效方法,分别分析了面积等效时截面惯性矩的精度和惯性矩等效时面积的精度.给出了计算蒙皮加筋圆柱壳弯曲固有振动频率和模态的等效梁模型、壳-梁模型和变厚度模型,这三种模型虽然皆可以用于火箭动态特性分析,但不同模型中的桁条作用机理不同.给出了与三维壳-梁模型和变厚度模型对应的一维解析解,据此解释了模型的物理机理.给出了薄壁壳弯曲频率计算中的临界厚度概念,指出了等效厚度方法的不足.

Three solution models of lateral frequencies of stiffening cylindrical shell

The equivalence methods of area and moment of inertia were studied for the stringers in stiffening cylindrical shell,and the accuracy of moment of inertia when the area was equivalent,and the accuracy of area when the moment of inertia is equivalent were investigated respectively.The concept of critical thickness of thin cylindrical shell was revealed in the calculation of lateral inherent frequencies and the deficiency of the equivalence thickness method was pointed out.The equivalence beam model,the three dimensional(3-D) shell-beam model and the 3-D varied thickness shell models were presented for the lateral free vibration analysis of stiffening cylindrical shell,although these models can be utilized to analyze the dynamic characteristics of rocket,the lateral effects of the stringers predicted by different models differ greatly.Moreover,one dimensional analytical solutions corresponding to both 3-D models with simply supports were given,from which the effects of stringers on the lateral frequencies were straight forward.