Simulation and Early Warning Design of Fire Resistance Characteristics of Steel Structure Towers for High Voltage Transmission Lines

Abstract

The dynamic simulations of stress evolution, surface and body temperature distribution of steel structure tower members of high voltage transmission lines (HVTL) under mountain fire conditions were carried out. The early-warning system of fire resistance performances of HVTL tower was established. The data analysis model for fire resistance characteristics and determination of collapse risk grade of such steel structure tower was developed. Based on distributed noncontact transducers of stress-strain and temperature, multi-antenna receiving mode of division-integration and remote server, the time-varying space temperature field of the mountain fire (A) was analyzed by using the tool of Ansys-Fluent, structural fire resistance performance of HVTL tower (B) was inspected by using the nonlinear finite element analysis tools such as ANSYS and SAP2000. By coupling (A) and (B), performing dynamic simulation, threshold comparison and image fitting, the variation profiles of temperature-stress-strain (T-ε) of overall tower can be obtained. Through the profiles the key mutation nodes and corresponding parameters can be figured out. Resultantly, the theoretical calculation, nonlinear finite element simulation and data analysis models for the fire resistance characteristics of the steel structure tower, the progressive stress loss, stress-induced deformation and determination of collapse risk level have been established. The research can provide guidance for the planning, design, operation and maintenance of steel towers with various structural configurations and voltage grades relating to overhead transmission lines, and realize the safety operation and structural failure warning of steel structure towers and smart grids that are involved in environments of mountain fires.