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一问题的提出由空气动力学可知:作用于结构物上的风荷P(t)是风速v(t)的二次函数 P(t)=Kv~2(t) (1)式中K是与空气密度、结构几何形状及迎风面积等有关的参数。自然界的风完全是时间t的随机函数。若将所有量级相同的风视为一集合V(t),用随机过程加以描述,则对应风荷的集合P(t)亦为一随机过程。对风的观测分析表明:过程V(t)具有平稳性、各态历经性和正态分布,且V(t)中任一样本均可表为稳态风(?)和脉动风v_r(t)两部分之和,即: v(t)=(?)+v_r(t) (2) 显然过程V(t)中脉动风的集合V_r(t)也构成了一个平稳的、各态历经的和正态分布但均值为零的随机过程。
The aerodynamics of the proposed problem is known: the wind load P(t) acting on the structure is a quadratic function of wind velocity v(t) P(t)=Kv~2(t) (1) where K is Parameters related to air density, structural geometry, upwind area, etc. The wind in nature is completely a random function of time t. If all winds with the same magnitude are considered as a set V(t) and described by a stochastic process, then the set of corresponding wind loads P(t) is also a random process. Observational analysis of the wind shows that the process V(t) has stationarity, ergodicity, and normal distribution, and any sample in V(t) can be expressed as steady-state wind (?) and pulsating wind v_r(t). The sum of the two parts, namely: v(t)=(?)+v_r(t) (2) Obviously, the set of fluctuating winds V_r(t) in process V(t) also constitutes a stable, ergodic A random process with a normal distribution but a mean of zero.