Advanced Materials Research Vols. 199-200

Abstract: An optimization design method is developed for the beam pumping unit, which is based on the API-RP-11L design criteria. The Response Surface Method is used to calculate the structural reliability of the beam pumping unit. The optimization design method not only provides an efficient and fast optimization tool for the modular design of the beam pumping unit, but also offers an integral design calculation in accordance with the API design code. The function and theory of this optimization design method are given by this paper, as well as some concrete calculation examples.

Abstract: On the basis of SolidWorks/Simulation FEA module, statics analysis and design optimization for bogie parameters determination test bench gantry framework are researched in this paper. Taking the optimization design of gantry framework main beam for example, an optimal mathematic model is established, the optimization goal is to reduce the quality of the main beam, and the constraints are displacement and stress. Simultaneously, the model is simulated by the SolidWorks/Simulation software. Compared with the initial design, the results show that the quality of main beam is reduced by 12.69%, the quality optimization goal of the gantry framework test bed is realized. Meanwhile, it not only reduced the design and manufacturing cost, but also enhanced the design efficiency.

Abstract: A new numerical integration method for dynamic finite element analysis is proposed in the paper. In the proposed algorithm, the acceleration change in a particular time step is first assumed to be curved variation, and then the displacement vector, velocity vector and acceleration vector at the current instance can be expressed in terms of the results at last time instance. Because of the curvilinear property of the acceleration change in a particular time interval, the complicated dynamical responding such as high-oscillatory modes can be captured with the present method. The efficiency and accuracy of the proposed algorithm are validated by two numerical examples and numerical results show that the present formulation has better accuracy than the Wilson’s method and the Newmark’s method used in the conventional finite element method.

Abstract: The modal experiment of the three-section crossbeam was carried out by single-input multi-output method. Identify the stiffness and damping with single-degree-of-freedom identification method. Use ANSYS software APDL programming language and experimental data to establish the finite element model of joint surface of three-section crossbeam. Use modal analysis method analysis the three-section crossbeam which establishes FEM modeling of joint surface. The comparison of the analysis result and experimental result are shown. The FEM result of the three-section crossbeam established FEM modeling of joint surface is basically tally with the experimental result, the modeling methods for joint surface is feasible.

Abstract: Through the optimization of the design process, the application of the finite element method and the structural parameters design have avoided blindness of product design, reduced unnecessary waste, waste of material and time for example. The fuzzy constraints has been determined by the sensitivity calculation , and the use numerical method and procedures of chart to analyze and compare, the target setting in the specified range has been searched for the structure. Thus the optimal design got achieved.

Abstract: The dynamic equivalent continuum model of beamlike space deployable lattice truss which is repetition of the basic truss bay is established based on the energy equivalence. The finite element model of the lattice truss is also developed. Free vibration frequencies and mode shapes are calculated and simulated based on equivalent continuum model and discrete finite element model. The analytical solutions calculated by equivalent continuum model match well with the finite element model simulation results. A prototype of deployable lattice truss consist of 20 truss bays is manufactured. The dynamic response of lattice truss with different truss bays are tested by dynamic vibration experiment, and natural frequencies of lattice truss with different length are obtained from acceleration response curves. The experiment results are compared with simulation results which verifies that the correctness of finite element model, which also validate the effectiveness of equivalent continuum model indirectly.

Abstract: The actiyator of chassis mechanism of sugarcane harvester was a cubage flow regulation circuit consisted of a timing variable pump and a compensated flow control valve. The optimal controlling system described its movement from processing time using differential and state equations. The shortest-time optimal controlling trajectory of spring force of the variable pump was a group of concentric circles based on minimum principle, which controlling signal switched on origin trajectory. Under the condition of optimal control, the stator was pushed by spring to a new balance spot which left off origin 15.5 millimeter in the shortest time of 1.12 seconds, which provided theory base to further controlling system design. Its stability and validity has been proved well in physical product research.

Abstract: Aiming at the defects in describing stress field near the crack tip with traditional finite element method (TFEM), a new finite element method based on interval B-Spline wavelet (IBSW) is put forward, the displacement interpolation functions of plate element are constructed by using the scaling functions of IBSW, finite element model of cracked plate based on IBSW is established, and the stiffness matrixes of plate element is derived. The first four natural frequencies and mode shapes of the cracked plate are obtained by using interval B-Spline wavelet finite element (IBSWFE). Comparison of the calculated results with those by ANSYS shows that IBSWFE method can get higher calculation precision with less elements in dealing with engineering singularity problems.

Abstract: It is well known that structural behaviors of composite solids are determined by topology of microstructures of different sizes. In this paper a concurrent topology optimization method for integrated design of materials and structures with periodical microstructure was presented. The microstructures were assumed to be uniform in macro scale and heterogeneous in micro scale and the optimization object was to minimize the material global compliances. Design variables for structure and material microstructures were defined, independently. SIMP (Solid Isotropic Material with Penalization) was adopted to ensure clear topologies in both macro and micro scales. Design variables for structure and material microstructures were integrated into one system by using the super-element method. Influences of Representative Volume Element sizes, material ratio of macro-scale and micro-scale on structural topology are investigated. Numerical experiments validate the proposed method which can be used as an innovative design concept for the lightweight structures.

Abstract: Airplane flutter scale model should maintain the load transfer characteristics of the original structure. It is a structural inverse problem for proper natural frequencies as well as structural simplification. This inverse problem could be solved by topology optimization. So based on bi-direction evolutionary structural optimization (BESO) method, a topology method for designing fuselage flutter model is presented. Facing porous and irregular shape often appears in topology optimization, a regular shaped grid frame structure consisted of the finite elements is discussed, including its internal mapping relationship and boundary conditions. The ratio criterion for structural modification is raised in this structural topology optimization using frequency sensitivity. Finally, this topology optimization method is applied to cylindrical fuselage flutter model design, result shown that the proposed approach is feasible to achieve given natural frequencies, maintains the character of inner frame structure completely, and the similarity between optimized structure and original structure is achieved.