**3.2 Solid isotropic material with penalization method**

Shao [55] has combined BESO with SIMP considering 3D printing applications. Lógó [56] has solved a continuum-type topology optimization problem considering uncertainties in load positions. Garcia-Lopez et al. [57] combined simulated annealing with SIMP to eliminate gray areas resulted by SIMP. Gebremedhen et al. [58] used SIMP to solve 3D stress-constrained topology optimization problems. Jantos et al. [59] used a new approach based on thermodynamics material modeling and not containing any filter and compared the results with SIMPs'. Jiao et al. [60] combined ESO with SIMP and used strain energy in their filtering function as sensitivity number. Kandemir et al. [61] proposed a new approach to define intermediate densities (gray areas) with new penalization factor. Marck et al. [62] applied SIMP to solve a multiobjective conductivity problem while using finite volume method (FVM) to solve the energy equation. Ospald and Herzog [63] used projected gradient method with SIMP to solve the structure problem of mold where short-fiber-reinforced polymer material is used in injection molding. Qiao et al. [64] applied the hybrid method of SIMP and BESO to a MBB beam and a cantilever beam and compared the results with literature. Schlinquer et al. [65] applied SIMP to design a mechanism used to amplify the displacement of a piezoelectric actuators. Tsai and Cheng [66] employed SIMP to design flywheel rotor having maximum stiffness. Wang et al. [67] combined topology and size optimization for a folding wing structural design. Yang et al. [68] accomplished topology optimization of an electric vehicle body by SIMP. Yang et al. [69] used SIMP for topology optimization of a hard disk drive. Yunfei et al. [70] applied SIMP to design a robot's upper arm. Zhang and Ren [71] proposed a new optimality criterion method concerning minimum compliance. Zhang et al. [72] presented a new approach to control the length scale of structural members. Zhang et al. [73] presented a method for cellular structures with multiple types of microstructures. Zuo and Saitou [74] introduced power functions with scaling and translation coefficients and the cost properties for multiple materials.
