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中文核心期刊

粘接-映射混合算法及其对颗粒材料中板的振动特性分析

THE COMPOSITE-MAPPING HYBRID ALGORITHM AND ITS APPLICATIONS OF VIBRATION PLATE BURIED IN PARTICLES

  • 摘要: 结构与颗粒材料相互作用广泛存在于各工程领域,其研究过程中涉及的连续-离散耦合计算方法面对诸多挑战.本文提出了粘接-映射混合算法来研究连续体与离散介质耦合动力学问题.将连续体模型划分为内部区域及与颗粒接触的边界区域.边界区域采用粘接算法模拟连续体外部形状并使用高效的球形接触判断准则;提出一种包含Rayleigh阻尼映射的有限元映射质点弹簧算法来精确计算连续体内部区域内力和变形.二者相结合构成粘接-映射混合算法,并引入计算机集群和GPU(图形处理器)并行技术,对埋没于颗粒材料中受激振动固支方板的连续-离散耦合动力学问题进行了数值仿真研究.结果表明,粘接-映射混合算法有利于双层级并行算法的程序实现及优化,并在连续-离散耦合界面进行快速接触判断的同时实现对颗粒材料中方板位移、变形、振动形态等参数的研究.通过定幅扫频和定频变幅方式考察激振力频率和幅值对振动板非线性动力学行为的影响并观察到二倍周期现象,同时给出了该连续-离散耦合系统中颗粒体系的能量耗散特性.

     

    Abstract: The interaction between structure and granular materials exists widely in various engineering fields, and the research method of this continuum-discrete coupling problems faces numerous challenges. The composite-mapping hybrid algorithm is presented to research dynamics of continuum-discrete coupling problems. The continuum model is divided into the inner region and the border region of particle contact. In the border region, the composite spheres method is applied to construct the profile of continuum efficiently in order to facilitate fast contact detection between the continuum and particles. In the inner region, the finite element mapping method is introduced to precisely calculate the internal force and deformation of continuum, and the method also contains Rayleigh damping mapping processes. The program with the composite-mapping hybrid algorithm is developed based on the compute cluster and GPU parallel computing technique. The numerical simulation of the square vibration plate which supported at four fixed edges and buried in particles is done to study continuum-discrete coupling dynamics problems. The results show that the proposed composite-mapping hybrid algorithm is appropriate for realization of the compute cluster and GPU paralleled computing technique and improvement of computational efficiency. In analysis on buried plate problems, motion and deformation of the plate can be easily and accurately measured by means of the algorithm. Simultaneously, contact detection can be achieved rapidly in the interface between continuum and discrete, and mechanical parameters of displacement, deformation and vibration modes can also be calculated. The influence of excitation frequency and amplitude on square plate's nonlinear vibration has been studied through excitation with constant amplitude-changing frequency and with constant frequency-changing amplitude, and the period-doubling has been found. Meanwhile, the energy dissipation of granular media in this continuum-discrete coupling system is provided.

     

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