Full-range analysis for nonlinear aerostatic instability of long span cable-stayed bridges

摘要

To investigate the full-range characteristic on nonlinear aerostatic of long span cable-stayed bridge. taking a cable-stayed bridge under construction for example, the realization process of inner and outer incremental double iteration method to solve the aerostatic stability and the full-range physical characteristics of instability are described in detail. Analysis result shows that the critical velocity and instability shape are relation with the corresponding three-component force coefficients of the initial attack angle and the slope of three-component force coefficient curve. Concretely, the iterative positive or negative changing direction of effective attack angle in full-range of aerostatic instability is ascertained by the positive or negative value of lifting moment coefficient in initial attack angle; in addition, which will influence the lifting force coefficient value and drag force coefficient value, the bigger the slope of lifting moment coefficient curve is, the smaller the critical velocity is; when the initial angle is located in the smallest of the positive and the biggest of the negative value of lifting moment coefficient curve, the critical velocity reach the maximum in different rotation direction separately, and with the increase of absolute value of lifting moment coefficient in effective attack angle, the critical velocity presents descending trend in those two different rotation directions.