Topology Optimization Of Hydraulic Steel Arche Gate Based On The Arms' Stability

Hydraulic steel arch gates are widely used in the hydraulic projects because of its advantages such as smoother flow,fewer embedded parts,smaller hoisting capacity and flexibly operating.Hydraulic steel arch gates belong to complex spatial structures.Structural arrangement form suggested by norm is not based on optimization of the overall structure but traditional experience,which leads to the coexistence of buckling failure of gates' arm and waste of materials.With the development of the topology optimization and computer technology,topology optimization is become more and more widely used in all walks of life.At present the application of topology optimization on the hydraulic arch steel gate is limited in the two dimensional optimization.What's more,it has not considered the stability and economic constraints of the arm.Therefore,it is very necessary to make light-duty and steady arrangement optimization for hydraulic steel arch gates based on the theory of topological optimization and structural stability.The work and results are as follows:Firstly,according to variable density method of continuous topological optimization theory,a three-dimensional topological optimization study is made based on general FEM software.In this study,the pseudo-density of elements is selected as design variable,the stiffness maximization as target,the volume fraction as constraint condition and the penalty factor as main control parameter.After a large number of topological optimization studies on non-dimensionalized table orifice radial gate,we come up with the functional relationship between Y shaped arm structure with penalty factor and volume fraction.Based on this a arch gate Y shaped arm structure is preliminary established.Secondly,in this paper we try to combine topology optimization theory,structural stability theory and structural optimization method.According to the early configuration we set up the double nonlinear stability analysis model which consider both geometry and material.In order to get the buckling safety factor of Y shaped arm,we did stability analysis using the energy method.Then the design code was selected as constraint condition and the stability bearing capacity maximization of unit mass as target,we did the optimization and got the optimal structural form of arch gate's Y shaped arm.Research shows: Firstly,the optimal topological configuration of hydraulic steel arch gates is y shaped tree structure in design pool level,no matter the gates open or close.Under the normal pool level the distance between the bifurcation and the hinge points is 0.355 times of the radius of the arch gate,it is 0.443 times under the instantaneous of the gate open.Secondly,the optimal topological configuration is decided by penalty factor and volume fraction.Penalty factor decides the shape of y shaped arm: the larger the penalty factor is,the closer the bifurcation is to the gate leaf.Besides,volume fraction decides the section size of y shaped arm.According to the method in this paper,we use a table orifice radial gate project as an example and the instantaneous of the gate open as controlling case.We compared the optimized structure with the original design structure,results show that the total mass of the optimal configuration under the normal pool level decreases 18.84%,which decreases 13.43% under the gate opening case.