Analysis On Wind Induced Dynamic Response Of Tensioned Cable-membrane

Cable-membrane structure is a new style of space structure which is composed of cable and membrane elements, and the structure is geometrical stable and stiffened only under the prestress. Cable-membrane structure is getting more and more favor of the architects and probably has a broadening application depending on its beautiful architectural shape and good bearing system. The feature of geometrical non-linearity must be taken into account in calculations, because of cable-membrane structure's flexible and large deflection after deforming. So far, the research on the cable-membrane structure's static property has been developed roundly, correspondingly, the research of it's dynamic property is deficiency. However for flexible system, cable-membrane structure will have a bigger response under the action of wind, so we should pay more attention to its dynamic property. At the same time, this is why I chose this subject.In this paper, the nonlinear finite element method equations are presented in detail, then the equations are used to do form-finding analysis of the tensile membrane structure. The examples prove the theory presented and the calculation program is correct. The natural vibration characteristics of the flexible cable-membrane structure after form finding is analyzed. The example indicates that the natural vibration frequency is low, and distributes continuously; the natural vibration frequency will raise with increasing the prestress of membrane and the elastic modulus of cable-membrane as well as the height span ratio of structure; the natural vibration frequency will reduce with increasing the span. Then AR model in linear filter theory is adopted to simulate the fluctuant wind load according to the Davenport wind spectrum and it meets the needs of velocity and pressure spectrum as well as spatial correlation. This program also takes the change of height into account. Then the time history records of fluctuating wind pressures are obtained considering the velocities coupling and the added air mass.The vibration laws of the structure under separate horizontal wind component, separate vertical wind component and the collective together horizontal wind component with vertical wind component has been analyzed. The example analysis shows that the response of structure will raise nonlinearly, when increasing wind velocity; The response will reduce and the breadth also reduce, when increasing the prestress of membrane; The response will raise, while the stiffness of structure will reduce, when increasing the span of structure; The response will have almost no change, when increasing the elastic modulus of membrane and the height span ratio of structure. The statistical analysis is done and the reference value of structural response factor which is around 2.0 as well as the amplification factor under the vertical wind component which is in the vicinity of 1.5~1.8 is provided.