Evolution Mechanism of Wind Vibration Coefficient and Stability Performance during the Whole Construction Process for Super Large Cooling Towers

Wind-induced damage during the construction process and the evolution of damage over time are important reasons for the wind-induced destruction of large cooling towers. In fact, wind vibration coefficient and stability performance will evolve with the construction height and material properties over time. However, the existing studies generally ignore the impact of wind load and structural performance during the construction period. In this study, we built the 3D physical model separately for all eight construction stages a super large cooling tower which is being currently constructed and stands 210 m. The dynamic characteristics of the cooling tower were analyzed in each stage. First, the flow field information and 3D time history of aerodynamic forces were obtained for the whole construction process using large eddy simulation (LES). Full transient dynamic finite element analysis was used to calculate the dynamic responses of the tower under the real-time changes of wind loads during the whole construction process. Five calculation methods were used to trace the evolution of wind vibration coefficient during the whole construction process of the super large cooling tower. Then the formula for wind vibration coefficient changing with the construction height was fitted. The differential values of wind vibration coefficient during the whole construction process of the cooling tower were discussed by taking the meridional axial force as the objective function. On this basis, the influence and working mechanism of wind vibration coefficient, concrete age, construction load, geometric nonlinearity, internal suction force on buckling stability, and ultimate bearing capacity of the cooling towers were investigated. This research provides an enhanced understanding on the evolution of wind-induced stability performance in super large cooling towers and a methodology to prevent wind-induced damage during the construction process.

Investigations on the Wind Vibration Coefficient of Single Layer Lattice Barrel Vault Structures

Wind actions on the structures consist of two parts, the average action and the fluctuation action. The fluctuation action will cause the structures vibrating and enlarge the wind action of the structures. This paper investigates the wind vibration coefficient for the single layer lattice barrel vault structures. In the analysis, the simulation velocity-time curve of wind is developed and the finite element methods are used to analyze the wind-induced vibration responses of the lattice barrel vault structures. The influence of the rise to span ratio, the length to width ratio of the structure, and the different average velocity of the wind are investigated. Based on the numerical analysis results, the formula of the wind vibration coefficient for the single layer lattice barrel vault structure is suggested for the wind resistance design of the structures.

Study on Wind Load Performance for L Type Aerial Work Suspended Platform

Based on the wind load calculation model increases Suspended Platform vibration characteristics of wind vibration coefficient, and gets Suspended Platform natural vibration period and inherent frequency by ANSYS finite element modal analysis, then determines the wind vibration coefficient, calculates the wind load of Suspended Platform in working state and non-working state. Aiming at three different conditions, analyzes the platform structure in the wind load the stress intensity and deformation. Through analysis to finds the most dangerous positions of Suspended Platform in three different conditions, provides effective references for the L Type Suspended Platform in wind-resistant design and optimization design.