摘要：With the fast development of computational mechanics and the capacity as well as the speed of modern computers,simulation-based structural optimization has become an indispensable tool in the design process of competitive *** paper presents a brief description of the current status of structural optimization by reviewing some significant progress made in the last *** research topics are also *** entire literatures of the field are not covered due to the limitation of the length of *** scope of this review is limited and closely related to the authors＇ own research interests.

摘要：An effective method to design structural Left-handed material（LHM） was proposed. A commercial finite element software HFSS and S-parameter retrieval method were used to determine the effective constitutive parameters of the metamaterials, and topology optimization technique was introduced to design the microstructure configurations of the materials with desired electromagnetic characteristics. The material considered was a periodic array of dielectric substrates attached with metal film pieces. By controlling the arrangements of the metal film pieces in the design domain, the potential microstructure with desired electromagnetic characteristics can be obtained finally. Two different LHMs were obtained with maximum bandwidth of negative refraction, and the experimental results show that negative refractive indices appear while the metamaterials have simultaneously negative permittivity and negative permeability. Topology optimization technique is found to be an effective tool for configuration design of LHMs.

摘要：Advanced programmable metamaterials with heterogeneous microstructures have become increasingly prevalent in scientific and engineering disciplines attributed to their tunable ***,exploring the structure-property relationship in these materials,including forward prediction and inverse design,presents substantial *** inhomogeneous microstructures significantly complicate traditional analytical or simulation-based ***,we establish a novel framework that integrates the machine learning(ML)-encoded multiscale computational method for forward prediction and Bayesian optimization for inverse *** prior end-to-end ML methods limited to specific problems,our framework is both load-independent and *** means that a single training session for a constitutive model suffices to tackle various problems directly,eliminating the need for repeated data collection or *** demonstrate the efficacy and efficiency of this framework using metamaterials with designable elliptical holes or lattice honeycombs *** accelerated forward prediction,we can precisely customize the stiffness and shape of metamaterials under diverse loading scenarios,and extend this capability to multi-objective customization ***,we achieve topology optimization for stress alleviation at the crack tip,resulting in a significant reduction of Mises stress by up to 41.2%and yielding a theoretical interpretable *** framework offers a general,efficient and precise tool for analyzing the structure-property relationships of novel metamaterials.

摘要：Lumbar degeneration leads to changes in geometry and density distribution of vertebrae,which could further influence the mechanical property and *** study aimed to quantitatively describe the variations in shape and density distribution for degenerated vertebrae by statistical models,and utilized the specific statistical shape model(SSM)/statistical appearance model(SAM)modes to assess compressive strength and fracture *** detailed SSM and SAM were developed based on the 75 L1 vertebrae of elderly men,and their variations in shape and density distribution were quantified with principal component(PC)*** vertebrae were classified into mild(n=22),moderate(n=29),and severe(n=24)groups according to the overall degree of *** computed tomography-based finite element analysis was used to calculate compressive strength for each L1 vertebra,and the associations between compressive strength and PC modes were evaluated by multivariable linear regression(MLR).Moreover,the distributions of equivalent plastic strain(PEEQ)for the vertebrae assigned with the first modes of SSM and SAM at mean±3SD were *** Leave-One-Out analysis showed that our SSM and SAM had good performance,with mean absolute errors of 0.335±0.084 mm and 64.610±26.620 mg/cm3,respectively.A reasonable accuracy of bone strength prediction was achieved by using four PC modes(SSM 1,SAM 1,SAM 4,and SAM 5)to construct the MLR ***,the PEEQ values were more sensitive to degeneration-related variations of density distribution than those of *** density variations may change the deformity type(compression deformity or wedge deformity),which further affects the fracture *** models can identify the morphology and density variations in degenerative vertebrae,and the SSM/SAM modes could be used to assess compressive strength and fracture *** above findings have implications for assisting clinicians in pathological dia

摘要：This paper presents a design theory and dynamic mechanical characterizations of the composite tape-spring hinge made by two parallel single tape ***,the theoretical models of moment-rotation angle on anisotropy tape springs with antisymmetric laminates are ***,the relationships of moment-rotation angle for tape-spring hinges with different sizes are simulated and analyzed by means of the finite element method (FEM),which is in good agreement with the results from theoretical ***,the dynamic vibration analysis for deployable composite tube hinges with different dampings is done during the process of deployment.

摘要：The smoothed finite element method (S-FEM) was originated by G R Liu by combining some meshfree techniques with the well-established standard finite element method (FEM). It has a family of models carefully designed with innovative types of smoothing domains. These models are found having a number of important and theoretically profound properties. This article first provides a concise and easy-to-follow presentation of key formulations used in the S-FEM. A number of important properties and unique features of S-FEM models are discussed in detail, including 1) theoretically proven softening effects;2) upper-bound solutions;3) accurate solutions and higher convergence rates;4) insensitivity to mesh distortion;5) Jacobian?free;6) volumetric-locking-free;and most importantly 7) working well with triangular and tetrahedral meshes that can be automatically generated. The S-FEM is thus ideal for automation in computations and adaptive analyses, and hence has profound impact on Al-assisted modeling and simulation. Most importantly, one can now purposely design an S-FEM model to obtain solutions with special properties as wish, meaning that S-FEM offers a framework for design numerical models with desired properties. This novel concept of numerical model demand may drastically change the landscape of modeling and simulation. Future directions of research are also provided.

摘要：New techniques have been developed to make materials with a periodic three-dimensional lattice structure. The high stiffness per unit weight and multifunction of such lattice structures make them attractive for use in aeronautic and astronautic structures. In this paper, epoxy-soaked continuous carbon fibres were first introduced to make lattice composite structures, which maximize the specific load carrying capacity. A micromechanical analysis of several designs, each corresponding to a different manufacturing route, was carried out, in order to find the optimized lattice structure with maximum specific stiffness. An intertwining method was chosen and developed as the best route to make lattice composite materials reinforced by carbon fibers. A sandwich-weaved sample with a three-dimensional intertwined lattice structure core was found to be best. The manufacturing of such a composite lattice material was outlined, In addition to a high shear strength of the core and the integral manufacturing method, the lattice sandwich structure is expected to possess better mechanical capability.

摘要：Traveling wave piezoelectric beam actuators(TWPBAs)present an advantageous structural configuration for self-moving actuators and hold significant promise for operation in confined ***,current research on TWPBAs faces several limitations,including deficient design methods of excitation and structural parameters,inadequate evaluation metrics,and lack of a quantitative relationship between these parameters and evaluation *** study presents a systematic approach to determining TWPBAs'structure and excitation parameters,proposes criteria for determining the excitation parameters through an established analytical model,and introduces an effective evaluation method for TWPBAs'*** the analytical model and evaluation metrics,we reveal:(1)the coupling relationship between excitation parameters and structural parameters,(2)the influence of participating mode pairs on vibration response,(3)the quantitative relationship between the evaluation metrics and excitation parameters is also *** conclusions are substantiated by the results of finite element analysis,laser vibration measurements,and motion test ***,the practical application of TWPBAs in pipeline operations underscores their potential for use in endoscopy and precision instruments.

摘要：A micromechanics analysis on the possibility of designing a two-phase pseudoelastic composite is made for the case where ductile transformable shape mem- ory alloy plastic particles are imbedded coherently in an elastic matrix. It is demon- strated that a pseudoelastic stress-strain loop in a macroscopic loading-unloading cy- cle can be obtained by microscopically stress induced forward and reverse martensitic transformations in the SMA particles. The relation between the macroscopic stress- strain response and the material parameters of the constituents of this composite is quantified through the micromechanics calculations, which reveals that the best duc- tility and thus the greatest energy absorption capacity of this novel microstructure can be obtained by the optimum material design.

摘要：Ocean currents are one of important resources of ocean energy. Although it is not widely harnessed at present, ocean current power has a vital potential for future electricity generation. In fact, several turbine systems have been proposed in the world. In the present, we consider what factors should be considered in designing the system from the perspective of hydrodynamics. As an example, a floating Kuroshio turbine system which is under development in Taiwan is employed to serve as the case study. The system consists of five major parts; i.e. a foil float which can be employed to adjust the system submergence depth, a twin contrarotating turbine system for taking off the current energy, two nacelles housing power generators, a cross beam to connect two nacelle-and-turbine systems, and two vertical support to connect the foil float and the rest of the system.