| Earthquake strength required for the destruction of non-structural components of buildings is usually much lower than that of structural components.In particular,pipeline systems are prone to damage in low-intensity earthquakes,and secondary disasters such as fire,floods,etc.are caused by water leakage,electricity leakage,and gas leakage.As an important part of the mechanical and electrical equipment system attached to the building,the anti-seismic support and hanger’s function is to transmit the seismic force received by the wind pipe,water pipe and power bridge frame to the building structural parts when an earthquake occurs,so as to avoid damage to the pipeline.Therefore,the seismic performance of seismic support hangers seriously affects the safety of pipeline structures,and improving the seismic performance of seismic support hangers is the starting point and goal of research.Therefore,this paper uses ABAQUS to establish a finite element analysis model of the pipeline system,and analyzes the influence of the seismic support and hanger structure parameters on the natural frequency and pipeline acceleration,velocity,displacement,and stress.Based on the central composite test and multi-objective optimization technology,the optimization design of seismic supports and hangers is realized.Establish an optimal design system for seismic support and hanger structure.The main research contents and results of the thesis are as follows:1.Theoretical Derivation of Mode Superposition Response Spectrum.The seismic response spectrum method is used to promote the calculation formulas of the relative displacement response spectrum,the relative velocity response spectrum,and the absolute acceleration response spectrum under the single-degree-of-freedom system.The seismic response spectrum method is combined with the principle of vibration mode superposition to establish the vibration mode superposition response spectrum method.The formulas of the maximum response values of speed,displacement and acceleration are derived to provide a theoretical basis for the design calculation of seismic support hangers.2.Establish a mechanical analysis model of lateral seismic support hanger.The mechanical analysis model of the lateral seismic support and hanger is obtained by simplifying the lateral seismic support and hanger model.The calculation formula of the maximum load of the dangerous point of the screw is calculated according to the superposition principle.According to the Euler formula,the formula for calculating the maximum load of the diagonal brace satisfying the stability condition of the compression bar is obtained.It is the foundation for the static analysis of seismic support hangers.3.Establish a finite element analysis model for the seismic support and hanger of the pipeline.ABAQUS was used to establish the finite element analysis model of pipeline seismic supports and hangers.The analysis obtained the first-order natural frequency and the response of the pipeline system under ground motion.By analyzing the influence of the structural parameters of the seismic support and hanger on the seismic performance,the three main influence parameters of the length of the reinforcement rod,the angle of the diagonal brace and the height of the support point are determined.Finally determine the best structural parameters and optimization interval under single factor.Through the central compound experiment,the minimum stress and maximum first-order natural frequency are used as the goal to establish a three-dimensional quadratic parameter equation with the length of the reinforcing rod,the angle of the diagonal brace,and the height of the brace support point as variables,so as to prepare for multi-objective optimization.4.Multi-objective optimization and experimental verification.Import the ternary quadratic parameter equation between the independent variable and the dependent variable into the Isight software,and use the NSGA-Ⅱ algorithm to obtain the Pareto optimal solution between the various parameters.The Pareto optimization solution provides multiple feasible solutions to find the best solution that meets the actual situation as reasonable as possible,and manufacture and process seismic supports and hangers based on this,and verify the performance of the seismic supports and hangers through cyclic loading experiments.The results show that the optimized maximum displacement is reduced by 14.69% from 43.64 mm to 37.23 mm.The maximum stress is reduced by 16.25% from 244.3MPa to 204.6MPa. |
