Achieving length scale control in topology optimization

Length scale control plays an important role in ensuring the manufacturability of topology optimization designs. By utilizing the intrinsic length scale embedded in the filtering techniques, a simple method is proposed in the present paper to achieve the minimum length scale control in density based topology optimization. With this method, the original element neighborhood is firstly replaced by the physical neighborhood, making the element center-to-center distance changes according to the refinement of the finite element meshes; second, the intrinsic length scale of filtering technique is used for representing the physical length scale in topology optimization designs. By applying the physical neighborhood, the problem of minimum length scale control is translated into the problem of adjusting the filter radius. The validity of the proposed length scale control method is tested through the classical compliance minimization problems. Experiment results reveal that the length scale of the structural member of topology optimization result is controlled to the specified size, and the filter features exhibited in the original element neighborhood are inherited.