A 172-line Matlab code for structural topology optimization in the body-fitted mesh

Topology optimization has the potential to be widely applied to produce innovative and efficient structures, allowing engineers to optimize their aesthetics and performance. This article adopted a 172-line Matlab code TriTOP172 to implement topology optimization in the unstructured triangular mesh using the bi-directional evolutionary structural optimization method. Its most significant feature is the elimination of zig-zag boundaries essentially existing in the commonly used rectangular mesh. The code uses 40 lines for preliminary setup and optimization iterations and a 78-line function to obtain the body-fitted mesh by solving the balance of a truss network. It also has a 20-line function of nonlinear diffusion to further smooth boundaries and control structure complexity and a 34-line function of finite element analysis. Numerical examples of compliance minimization are provided to assist readers in understanding the algorithm and its implementation. This code can be employed with further extensions to solve complicated conceptual design problems efficiently in several engineering fields. The educational Matlab program is accessible on the website and displayed in the Appendix.