摘要：topology optimization of continuum structures with design-dependent loads has long been a challenge. In this paper, the topology optimization of 3D structures subjected to design-dependent loads is investigated. A boundary search scheme is proposed for 3D problems, by means of which the load surface can be identified effectively and efficiently, and the difficulties arising in other approaches can be overcome. The load surfaces are made up of the boundaries of finite elements and the loads can be directly applied to corresponding element nodes, which leads to great convenience in the application of this method. Finally, the effectiveness and efficiency of the proposed method is validated by several numerical examples.

摘要：Micro-mass sensors have attracted increasing attention in the field of biomolecular and chemical detec- tion. It has been found that the size, shape, and geometry of the structure may affect the performance of the sensor. As a result, a topology optimization methodology is proposed in this paper for the design of micro-mass sensors. A phase- field function controlled by nodal variables and finite element shape functions is used to describe the configuration of a sen- sor in the constructed optimization problem. The design goal is to maximize the mass detection sensitivity. On the basis of these formulations, an optimization algorithm is constructed using the finite element method and the method of moving asymptotes. Numerical examples are presented to demon- strate the validity of the proposed problem formulation. The results suggest that the performance of the micro-mass sensor can be improved by using the proposed approach.

摘要：topology optimization is an effective method to obtain a lightweight structure that meets the requirements of structural *** the optimization results meet the actual needs mainly depends on the accuracy of the material properties and the boundary conditions,especially for a tiny Flapping-wing Micro Aerial Vehicle(FMAV)transmission system manufactured by 3D *** this paper,experimental and numerical computation efforts were undertaken to gain a reliable topology optimization method for the bottom of the transmission ***,the constitutive behavior of the ultraviolet(UV)curable resin used in fabrication was ***,a numerical computation model describing further verified via *** optimization modeling considering nonlinear factors,***,friction and collision,was presented,and the optimization results were verified by both dynamic simulation and ***,detailed discussions on different load cases and constraints were presented to clarify their effect on the *** methods and results presented in this paper may shed light on the lightweight design of a FMAV.

摘要：The hoist bracket links the rescue hoist with the helicopter cabin, and its structure design greatly affects the operation convenience and safety of the hoistman and lifeguard in the rescue process with a *** paper firstly builds the force model of the hoist and bracket, and gives five kinds of typical working conditions as the design ones of the bracket. Then this paper puts forward a design process of the hoist bracket based on the topology optimization and strength analysis with the 3D modeling and finite element analysis. This design process can make the bracket's structure lightweight by achieving the optimal material layout under the conditions of maximizing the static stiffness or minimizing the compliance of the bracket. And this improves the dynamic performance of the helicopter, and reduces the fuel consumption and cost under the strength constraints. Finally,taking the design of the hoist bracket used in a rescue helicopter as an example, this paper illustrates the proposed model and method. The analysis results show that the mass of the hoist bracket decreases by 12.5% while the static stiffness of the hoist bracket is achieved. The optimization design results meet the strength requirements of the hoist.

摘要：topology optimization design of continuum structures that can take account of stress and displacement constraints simultaneously is difficult to solve at present. The main obstacle lies in that, the explicit function expressions between topological variables and stress or displacement constraints can not be obtained using homogenization method or variable density method. Furthermore, large quantities of design variables in the problem make it hard to deal with by the formal mathematical programming approach. In this paper, a smooth model of topology optimization for continuum structures is established which has weight objective considering stress and displacement constraints based on the independent_continuous topological variable concept and mapping transformation method proposed by Sui Yunkang and Yang Deqing. Moreover, the approximate explicit expressions are given between topological variables and stress or displacement constraints. The problem is well solved by using dual programming approach, and the proposed element deletion criterion implements the inversion of topology variables from the discrete to the continuous. Numerical examples verify the validity of proposed method.

摘要：Component sequence preservation is an intrinsic requirement in typical engineering applications, such as deployable chain-likestructures, 3D printing structures with contour-parallel toolpaths, additive manufacturing of continuous fibre-reinforcedpolymer structures, customized stents, and soft robotics parts. This study presents a feature-driven method that preservescomponent sequences accounting for engineering requirements. The chain-of-bars design variables setting scheme is developedto realize the sequential component’s layout, which sets the current bar’s end point as the next bar’s start point. The total lengthof the printing path is constrained to reduce the consumption of material accurately. Also, the angle between adjacent bars isconstrained to avoid sharp angles at the turning point of the 3D printing path. Next, the sensitivity analysis considering theinter-dependence of substructures is performed. Several numerical examples are given to demonstrate the validity and merits ofthe proposed method in designing structures preserving component sequences.

摘要：In topology optimization of structures considering flexibility, degenerated optimal solutions, such as hinges, gray areas and disconnected structures may appear. In this paper, built upon the newly developed morphable component based topology optimization approach, a novel representation using connected morphable components(CMC) and a linkage scheme are proposed to prevent degenerating designs and to ensure structure integrity. A lower bound condition of the thickness of each component is also incorporated to completely remove the smallest components in an optimal configuration. Designs of flexible structures, such as compliant mechanism design, maximum compliance structure design, and design of low-frequency resonating micro devices are studied to validate the proposed methodology. Our work demonstrates that the new methodology can successfully prevent degeneration solutions and possesses other advantages, such as minimum member size control in topology optimization of flexible structures.

摘要：Design and application of tunable phononic crystals(PnCs)are attracting increasing interest due to their promising capabilities to manipulate acoustic and elastic waves *** paper investigates topology optimization of the magnetorheological(MR)materials including PnCs for opening the tunable and wide ***,the bandgap tunability of the PnCs is achieved by shear modulus variation of MR materials under a continuously changing applied magnetic *** pseudo elemental densities representing the bi-material distribution inside the PnC unit cell are taken as design variables and interpolated with an artificial MR penalization *** aggregated bandgap index for enveloping the extreme values ofbandgap width and tunable range of the MR included smart PnCs is proposed as the objective *** this context,the sensitivity analysis scheme is derived,and the optimization problem is solved with the gradient-based mathematical programming *** effectiveness of the proposed optimization method is demonstrated by numerical examples,where the optimized solutions present tunable and stably wide bandgap characteristics under different magnetic *** tunable optimized PnCs based device that can provide a wider tunable bandgap range is also explored.

摘要：The design of compliant hinges has been extensively studied in the size and shape level in the *** paper presents a method for designing the single-axis flexure hinges in the topology *** kinds of hinges,that is,the translational hinge and the revolute hinge,are *** basic optimization models are developed for topology optimization of the translational hinge and the revolute hinge,*** objective for topology optimization of flexure hinges is to maximize the compliance in the desired direction meanwhile minimizing the compliances in the other *** constraints for accomplishing the translational and revolute requirements are *** popular Solid Isotropic Material with Penalization method is used to find the optimal flexure hinge topology within a given design *** results are performed to illustrate the validity of the proposed method.

摘要：The paper presented topology optimization of 2 D and 3 D Nanofluid-Cooled Heat Sink(NCHS). The flow and heat transfer problem in the NCHS was treated as a single-phase nanofluid based convective heat transfer model. The temperature-dependent fluid properties were taken into account in the model due to the strong temperature-dependent features of nanofluids. An average temperature minimum problem was studied subject to the fluid area and energy dissipation constraints by using the density method. In the method, the design variable is updated according to the gradient information obtained by an adjoint based sensitivity analysis process. The effects of the energy dissipation constraint, temperature-dependent fluid properties and nanofluid characteristics on optimal configurations of NCHS were numerically investigated with following ***, branched flow channels in the optimal configuration increased with the rise of the allowed energy dissipation. Secondly, temperature-dependent fluid properties were significant for obtaining the appropriate optimal results with best cooling performance. Thirdly, heat transfer performances of optimal configurations were enhanced by reducing the nanoparticle diameter or increasing the nanoparticle volume fraction. Fourthly, the optimal configuration for nanofluid had better cooling performance than that for its base fluid.