Structure topology optimization method for output loads precise control

With the improvement of the aircraft performance, the design of load carrying structures becomes more and more complicated. The input load should be distributed properly to the load carrying structure by the design of load path, which is of vital importance to make full use of load carrying capacity of the material, save the structural weight and ensure the load carrying capacity of the structure. For this reason, the purpose of this paper is to propose a new continuum structure topology optimization method that controls the output loads precisely. Under given input loads and boundary conditions, the magnitudes of the output loads are precisely designed to demanding values. To have a convenient modelling of the output load, we propose to apply some artificial bar elements at the output positions instead of standard boundary conditions. The constraints on output loads are then equivalently transferred to the constraints on nodal displacements of the bars, which are much simpler to be controlled. These constraints, as well as the design objective of minimizing structural compliance and the material volume constraints, formulate a new density based topology optimization model. Numerical examples tested in this paper have validated the effect of the proposed optimization scheme. The influence of the material usage, constraint bounds and ratio of output loads on the optimized design are also analyzed in details.