Seismic Reliability Assessment of a Structure with Elasto-Plastic Hysteresis

本文提出了一种近似解析方法，用于求解具有双线性滞回的单自由度机械系统在调幅非白随机激励下的非平稳响应。通过引入一个附加状态变量和非线性函数来描述滞回特性。利用截尾高斯概率密度函数和一对δ函数组成的非高斯概率密度函数，导出了等效线性系统的等效线性系数和等效线性系统的矩方程。通过求解弯矩方程，计算了滞回系统的均方响应和滞回耗能，并与相应的数值模拟结果进行了比较。两类随机振动平稳响应的功率谱和均方根值 ...更多信息 随机激励，即，测量了白色噪声和具有一个主导频率的非白色噪声。通过假定双线性滞回模型和使用力矩方程方法进行了理论分析。一个相当好的协议之间的理论和实验结果。结果表明，即使在低输入水平下，滞回效应对能量耗散响应的影响也是存在的。研究了部分充液圆柱形贮箱中液面的参数振动。贮箱承受水平、垂直和俯仰激励。在晃动响应分析中考虑了液面振荡的非线性。应用Galerkin方法导出了轴对称液面振动的非线性参数常微分方程组，该方程组包含了高阶径向模态。研究结果表明，参数激励是由垂直激励引起的。此外，当俯仰轴与圆柱形贮箱的对称轴不相交时，俯仰激励也会引起参数激励。利用模型水池进行了实验。本文提出了用随机过程来预测结构在地震激励下的动力特性的随机反应谱方法，其样本函数之一可以看作是记录的强震加速度记录。该方法包括模拟记录的地面运动的随机过程和均方根响应分析的一个单自由度系统使用的力矩方程法。随机反应谱作为最大均方根响应与系统固有周期的关系曲线，并与常规反应谱进行了比较。少

An approximate analytical technique is developed for obtaining the nonstationary response of a single-degree-of-freedom mechanical system with bilinear hysteresis subjected to amplitude modulated nonwhite random excitations. The hysteretic behavior is described by introducing an additional state variable and nonlinear functions. The equivalent linear coefficients and also the moment equations of the equivalent linear systems are derived using a non-Gaussian probability density function which is composed of a truncatd Gaussian probability density function and a couple of delta functions. The mean square responses and the mean dissipated hysteretic energy are calculated by solving the moment equations and are compared with the corresponding digital simulation results.An experiment is conducted by using a lead cantilever beam with a mass in order to examine the random vibrations of a hysteretic system. Power spectra and root mean square values of the stationary responses to two types of r … More andom excitation, i.e., white noise, and nonwhite noise with a dominat frequency, are measured. A theoretical analysis is carried out by assuming a bilinear hysterersis model and using the moment equations approach. A fairly good agreement is found between the theoretical and experimental results. It is shown that the effect on the response of energy dissipation due to hysteresis is observed even in the case of low input level.Parametric vibration of the liquid surface in a partially filled circular cylindrical tank is investigated. The tank is subjected to horizontal, vertical and pitching excitations. Nonlinearity of the liquid surface oscillation is considered in the response analysis of the sloshing motion. The nonlinear and parametric ordinary differential equations, governing the axisymmetric liquid surface oscillation and including the higher order radial modes, are derived by applying Galerkin's method. It is confirmed that the vertical excitation causes the parametric excitation. In addition, it is noted that the pitching excitation also causes the parametric excitation when the pitching axis does not intersect the symmetrical axis of the circular cylindrical tank. An experiment was conducted using a model tank. Good agreement was found between the theoretical and experimental results.The stochastic response spectrum approach is presented for predicting the dynamic behavior of structures to earthquake excitation expressed by a random process, one of whose sample functions can be regarded as a recorded strong-motion earthquake accelerogram. The approach consists of modeling recorded ground motion by a random process and the rms response analysis of a single-degree-of freedom system by using the moment equations method. The stochastic respone spectrum is obtained as a plot of the maximum rms response versus the natural period of the system and is compared with the conventional response spectrum. Less