instaneous meaning in English

瞬时的

First , the dynamic stability of braid composite cylindrical shells with the influences of some main factors is introduced . the general governing equations for the nonlinear dynamic stability is obtained . by the hamilton principle . the creep buckling analysis of braid composite cylindrical shells under axial compression and the dynamic stability under nonconservation force are discussed as emphases . in creep buckling question , by means of theoretical analysis , the instaneous critical load and durable critical load of viscoelastic braid composite cylindrical shell under axial compression are obtained and the numerical example is given
首先介绍了编织复合材料圆柱壳在几种主要因素影响下的动力稳定性问题，用hamilton原理建立非线性动力稳定性问题的一般性基本方程。然后重点讨论了编织复合材料圆柱壳轴压下的蠕变屈曲问题及非保守力作用下的屈曲问题。对蠕变屈曲问题，通过理论分析来得到了编织复合材料圆柱壳的瞬时弹性临界载荷和持久临界载荷，给出了具体的算例。