Mechanical Structure Optimization Research Articles

Thermal–Mechanical Performance Analysis and Structure Optimization of the TSV in 3-D IC

The through-silicon via (TSV) technology is widely used in 3-D integrated circuit (3-D IC) devices. However, the TSV could cause great thermal stress due to the mismatch of the thermal expansion between different materials, which affects the performance of the 3-D IC. In this work, a finite element model of the 3-D IC device with both internal pin-fin microchannels and all-copper interconnection is established. A substructure model is further developed and validated against the results obtained from the full model. Then, the thermal-mechanical performances of the TSV structure under thermal cycling loads are investigated based on the substructure model. The results show that the maximum stress locates at the edge of the interface between TSV_copper and memory, and the deformation on the TSV_copper-memory interface is dominated by shearing, which may cause the debonding of the interface. Moreover, the influences of the TSV structure parameters on the maximum thermal stress and TSV_copper's electrical resistance are analyzed. Then, the TSV structure is further optimized to reduce the stress and improve the electrical conductivity. Compared with the original design, the maximum von Mises stress and TSV_copper resistance of the optimized structure can be reduced by 18.4% and 40.6%, respectively.

Mechanical Response and Structure Optimization of Nanomodified Asphalt Pavement

Nanomaterials are widely used in the preparation of modified asphalt because they can improve the high‐temperature performance of matrix asphalt and have achieved good engineering results. However, the existing research mainly focuses on the material analysis and formula development of nanomodified asphalt and has not yet been involved in the mechanical response of the nanomodified asphalt pavement structure. The mechanical response contains the horizontal tensile stress and the vertical compressive stress of SiO2 modified asphalt pavement. It is unable to propose the matching pavement structure combination for the unique material characteristics of nanomodified asphalt, which leads to the increase of the possibility of pavement diseases and material waste. Hence, considering that semirigid base is the most widely used base type in China, two different structural models of nanomodified asphalt pavement are established according to the current specifications. The effects of pavement thickness, material type, and pavement design parameters on the mechanical response of nanomodified asphalt pavement are analyzed, and then the principle of optimal mechanical performance is taken and the optimal combination of nanomodified asphalt pavement structure is proposed.

Mechanical structure optimization of energy storage tank group in MEES system

The energy storage component of the MEES system is mechanical elastic energy storage tank group. Whether the mechanical structure design of energy storage tank is reasonable or not directly determines the performance of the whole system. In this paper, the structural design scheme of series linkage energy storage tank group is proposed, which can take into account the energy storage capacity and power demand. Firstly, the structural group of energy storage tank group is analyzed. Secondly, the operation mode of energy storage and power generation process of energy storage tank group is described in detail. Finally, the mathematical model of energy storage/generation operation is established, which provides theoretical guidance for the configuration of capacity and power of energy storage tank group.

Research status and development trend of concrete spiral distributor

Concrete distributor is one of the key equipment for the industrial production of concrete product parts. Its performance directly affects the product quality and production efficiency of precast concrete components, which in turn affects the level of architecture industrialization of China. At present, the domestic concrete distributor has a low degree of automation and a simple mechanical structure. There is too much manual intervention in the production. It is impossible to achieve a real automatic distribution. Also, BIM data cannot be shared with the control system, resulting in low production efficiency. This paper summarized these problems which are in the context of big data, internet of things and intelligence, and proposed the upgrade ideas for precast concrete components production equipment. In order to break through the bottleneck that restricts the stability, refinement and intelligent development of precast concrete components distribution. The research and exploration in BIM data analysis mechanical structure optimization and control system upgrade were conducted. Then the overall development of mechanical equipment that meets construction standards of China will be promoted.

Mechanical Performances and Structure Optimization of H-shaped Steel and Cement- Soil Wall

Mechanical Performances and Structure Optimization of H-shaped Steel and Cement- Soil Wall

Dynamic Analysis and Mechanical Structure Improvement of Submersible Rotor

In order to enhance interference immunity and reduce the breakage of rotating shafts (rotors) which happens frequently especially in submersible permanent magnet synchronous motor (PMSM) applications, first a typical rotor structure is established serving as the comparative object, and then two improved schemes with optimal mechanical structure are proposed. Rotor strength, rotor stiffness, and the influence of unilateral magnetic pull on the rotor deflection are calculated analytically. The modal simulation, stress field simulation, and unilateral magnetic pull simulation are analyzed using finite element method (FEM). Position deviation and bending deformation of the rotor caused by the unilateral magnetic pulling force is taken into account to improve the simulation accuracy. The simulation results illustrate that the submersible rotor improved by the proposed schemes presents more excellent stiffness and strength performance compared with the traditional scheme, which indicates that the proposed schemes have important reference values for the structural design of submersible rotor.

多功能共享单车机械结构设计与优化

多功能共享单车机械结构设计与优化

Mechanical Structure Design and Optimization Analysis of a new wave Energy Converter

This paper introduces the structural design of a novel wave energy converter, which are mainly divided into energy absorption and energy conversion sections. The upper and lower absorber blades in the energy absorbing section can convert the oscillating wave energy into mechanical energy. The energy conversion section selects a permanent magnet direct-current generator, which can convert the rotating mechanical energy into a direct-current electrical energy output to power a load or a lithium battery. According to the features of large energy and low speed of the wave energy absorbers, the gear ratio of the gear reducer is selected so that the operation of the absorber meets the requirement of the generator working speed.

Optimized Design of Space Solar Array Simulator With Novel Three-Port Linear Power Composite Transistor Based on Multiple Cascaded SiC-JFETs

Space solar array simulators (SSASs), which are used for testing space power systems, generally utilize linear power topologies owing to their fast dynamic performance and satisfactory simulation accuracy. However, to output a medium power level from a linear-power-topology SSAS, multiple parallel linear voltage-controlled current sources are required for addressing the redundant power dissipation, thereby limiting the overall mechanical structure and volume optimization; in addition, the presence of multiple parallel sources results in a complex circuit structure with poor reliability. In this context, in this study, we propose a novel three-port linear power composite transistor as a linear power dissipation device, which is composed of multiple cascaded SiC-JFETs to improve on the above-mentioned shortcomings. The proposed 510-W optimized SSAS requires only eight parallel linear current-source paths to form a linear power stage and uses a high-speed field-programmable gate array (FPGA) digital controller to quickly react to a load step between short circuit and open circuit (the harshest working condition for a solar array simulator) at a 1-kHz stepping frequency. Further, the device can react to a load step between short circuit and the nominal working point at 10-kHz stepping frequency, thus, offering a better dynamic performance over other similar devices.

Optimal design of a unimorph piezoelectric cantilever devoted to energy harvesting to supply animal tracking devices

This paper presents the mechanical structure optimization of a piezoelectric energy harvesters devoted to supply embedded animal tracking devices. The harvester mechanical structure being a bilayer unimorph piezoelectric cantilever is composed of two elements: a piezoelectric layer and a non-piezoelectric layer (i.e, active and passive layers). The suggestion of this paper is to find the optimal ratio between their two thicknesses in order to maximize the output recuperated voltage at the electrodes. For that, from the model that links the mechanical excitation moment and the output electrical charge, a gradient-based optimization is carried-out. Comparison with existing mechanical piezoelectric harvester structure is made and which clearly demonstrates that the proposed structure permits to gain up to five-times in terms of the output charge and a significant gain in terms of output electrical power for the same condition.

Parameterized unit-cell models for stiffness performance analyses of three-dimensional n-directional braided composites

Parameterized unit-cell models of three-dimensional n-directional ( n = 5, full-5, 6, or 7) braided structures are established based on the internal structures of three-dimensional braided composites. Braiding structures are characterized by model parameters, and the relationships between fiber volume fraction and model parameters are analyzed in this study. A finite element stiffness prediction is conducted using the parameterized models, and the simulation results are found to be consistent with the experimental data. Model parameters’ influence on elastic constants of the composites is studied through finite element method. The research shows that the models can describe braiding structures precisely and are applicable to stiffness performance analyses, and provides an available approach to mesoscopic mechanical analysis and structural optimization design of three-dimensional braided composites.

Reconstruction of Input Excitation Acting on Vibration Isolation System

Vibration isolation systems are widely employed in automotive, marine, aerospace, and other engineering fields. Accurate input forces are of great significance for mechanical design, vibration prediction, and structure modification and optimization. One-stage vibration isolation system including engine, vibration isolators, and flexible supporting structure is modeled theoretically in this paper. Input excitation acting on the vibration isolation system is reconstructed using dynamic responses measured on engine and supporting structure under in-suit condition. The reconstructed forces reveal that dynamic responses on rigid body are likely to provide more accurate estimation results. Moreover, in order to improve the accuracy of excitation reconstructed by dynamic responses on flexible supporting structure, auto/cross-power spectral density function is utilized to reduce measurement noise.

Mechanical structure optimization in minimum-time motion control of flexible bodies

This paper considers the problem of minimum-time motion control of a flexible body for which the dynamic properties can be optimized within a structural design. This allows a matching of modal characteristics to a control task such that reductions in time-of-motion can be achieved compared with unoptimized designs. The problem formulation is based on an elastic structure undergoing a motion task with specified boundary conditions and subject to limits on actuation forces. A numerical method for calculating minimum-time control input solutions based on an iterative construction of the reachable set is first considered. A structural optimization approach is further developed based on continuity properties of the solution set, these admitting a first order perturbation analysis from which an optimization of system design parameters can be achieved. A selection of numerical case studies are presented involving single and multi-mode structures. Possibilities for realization of the approach using variable stiffness/deformable structures are discussed and results from a linear motion stage with tunable-stiffness flexible armature presented that demonstrate the potential benefits.

New Concept for Design and Control of 4 Axis Robot Using the Additive Manufacturing Technology

This work introduces a new concept for designing and manufacturing an industrial robot by using modern production techniques and a 3D modelling software. The most important requirements of this project were to build a customized, lightweight and low cost robot, capable to fulfil many industrial working tasks such as palletizing mobile telephone covers. For designing and optimizing the mechanical structure of the palletizing robot a SolidWorks- software was used. Integrating motion simulation tools in SolidWorks intensely reduces the engineering time for finding the optimal mechanical structure of the robot according to the industrial task. The robot parts are produced by using the additive manufacturing technology- powder material PA 2200. For solving the forward and inverse kinematics of the robot, the Software tool SimMechanics from MathWorks was used. This environment provided by the software enables building a human machine interface in order to store and program the robot targets. This project additionally shows the new benefited experience about mechanical structure of robots using the powder material PA 2200. Furthermore the advantages and disadvantages of this concept will be comprehensively explained.

The Bionic Optimization and Analysis and Calculation of the Cast-Steel Joint with Three Branches

The tree-like structure is a branch of space bionic structures,belonging to the Bionic Architectural Structures. Cast-steel joints with branches are the keys to build the tree-like structures.They are used widely,and the most common joints in our projects are cast-steel joints with two、three and four branches. The cast-steel joints with two branches are planar,while the joints with three and four branches are spatial.Until now,the basic theoretical researches about the cast-steel joints with branches are also relatively scarce.This paper did researches about mechanical properties, calculation methods and structural optimization of the cast-steel joints with three branches deeply and systematically. The result shows that the bending moment has a big influence on the value of the max stress. And the three main failure modes of the cast-steel joint with three branches are yield of the main tubular along the axial direction, local buckling at the connection of the main tubular and branches, and the tearing out of the branches.

Mechanical Analysis and Structural Optimization to theTraining Device for Squatting

As for squat trainer, acommon fitness equipment, we do mechanical analysis and structural optimization from manufacturing costs and safety. With physical structure analysis and intensity check, we have materials and structural optimization for the equipment. This analysis method can be extended to other fitness equipment.

Real Coded Quantum Genetic Algorithm and its Application

Optimization design, as a new branch of science in recent years, is the result of optimization technique and computer technology applied in design. Optimization design provides an important scientific design method for engineering designer, which seeks the most perfect and optimum design proposal and greatly improves design efficiency and quality. Genetic Algorithm (GA) is an overall random searching method based on the Darwin's evolution and Mendelian. Genetic algorithm has better adaptability and wide accomodation. But it also has the disadvantages of poor local search ability, slow convergence and other defects. Quantum Genetic Algorithm (Quantum Genetic QGA) is produced by combining Quantum computing and Genetic Algorithm. And it is got enormous attention because of its small population size, higher ability to find the global optimal value, fast convergence rate and time-saving. A new algorithm named Real Coded Quantum Genetic Algorithm (RQGA) is proposed. After systematically introduce algorithm flow chart, key techniques and characteristics of SA and QGA, based on the characteristics of mechanical optimization problems, this paper proposes a new real number coded quantum genetic algorithm, and introduces coding method, operators, algorithm flow chart and etc. Furthermore, this paper also describes the algorithm implementation based on a Java language. Take reducer that is widely used in mechanical for example, and study the application of RQGA in the mechanical structure optimization design. Establish the optimization model is established and is resolved by using RQGA. Then the solution of SA and QGA are analyzed and compared. And the comparison shows the validity and feasibility of the RQGA.

Optimal Design, Fabrication, and Control of an $XY$ Micropositioning Stage Driven by Electromagnetic Actuators

This paper presents the optimal design, fabrication, and control of a novel compliant flexure-based totally decoupled XY micropositioning stage driven by electromagnetic actuators. The stage is constructed with a simple structure by employing double four-bar parallelogram flexures and four noncontact types of electromagnetic actuators to realize the kinematic decoupling and force decoupling, respectively. The kinematics and dynamics modeling of the stage are conducted by resorting to compliance and stiffness analysis based on matrix method, and the parameters are obtained by multiobjective genetic algorithm (GA) optimization method. The analytical models for electromagnetic forces are also established, and both mechanical structure and electromagnetic models are validated by finite-element analysis via ANSYS software. It is found that the system is with hysteresis and nonlinear characteristics when a preliminary open-loop test is conducted; thereafter, a simple PID controller is applied. Therefore, an inverse Preisach model-based feedforward sliding-mode controller is exploited to control the micromanipulator system. Experiments show that the moving range can achieve 1 mm t 1 mm and the resolution can reach ±0.4 μm. Moreover, the designed micromanipulator can bear a heavy load because of its optimal mechanical structure.

Mechanical Analysis and Structural Optimization of the Parabolic Trough Solar Collector

Parabolic trough solar thermal power generation system is always restricted by high drive torque, low thermal efficiency and high investment cost. In this paper, the parabolic trough solar collector in a solar energy application base is taken as the research object and FEM was used to realizing its structural light-weighting design. The structural overall performance is improved to lay a foundation for innovating drive mode and expanding the rotation scope. Beginning of the paper, the wind load characteristic was analyzed and its computational formula was provided the magnitude of wind load was computed; then, the static performance of the solar collector was analyzed by using ANSYS Workbench and the worst working condition of each static characteristic was confirmed to service for the later structural optimization; last, the overall optimization scheme of the solar collector was put forward, the position of the reflectors supporting point and the structure of the solar collectors cantilever was optimized.

The Closed Method of Solving in Inverse Solution of Position in Delta Parallel Mechanism

Delta mechanism with the smooth and flexible movement,reliable structure, is a kind of parallel mechanism.Through inversely solving the Delta mechanism space position is to set up a kind of equivalent relationship and through analysis of the mechanism is to solve the rotating angle of the hinge that is between connecting rods that are equivalents of three parallelograms,and the base platform.Through inverse solution of kinematics before building the whole mechanism,the range of the center in mobile platform can be found intuitively from graphics when it is satisfied with the restriction condition.According to requirements, the optimization of mechanical structure can be achieved.