• 제목/요약/키워드: fictitious mass and damping

검색결과 2건 처리시간 0.019초

The dynamic relaxation method using new formulation for fictitious mass and damping

  • Rezaiee-Pajand, M.;Alamatian, J.
    • Structural Engineering and Mechanics
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    • 제34권1호
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    • pp.109-133
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    • 2010
  • This paper addresses the modified Dynamic Relaxation algorithm, called mdDR by minimizing displacement error between two successive iterations. In the mdDR method, new relationships for fictitious mass and damping are presented. The results obtained from linear and nonlinear structural analysis, either by finite element or finite difference techniques; demonstrate the potential ability of the proposed scheme compared to the conventional DR algorithm. It is shown that the mdDR improves the convergence rate of Dynamic Relaxation method without any additional calculations, so that, the cost and computational time are decreased. Simplicity, high efficiency and automatic operations are the main merits of the proposed technique.

동적이완법을 이용한 Steel Lazy Wave Riser의 정적형상 추정에 관한 수치해석적 연구 (Numerical Study on Estimation of Static Configuration of Steel Lazy Wave Riser Using Dynamic Relaxation Method)

  • 오승훈;정재환;박병원;권용주;정동호
    • 한국해양공학회지
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    • 제32권6호
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    • pp.466-473
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    • 2018
  • This paper presents an estimation method for the static configuration of a steel lazy wave riser (SLWR) using the dynamic relaxation method applied to estimate the configuration of structures with strong geometric non-linearity. The lumped mass model is introduced to reflect the flexible structural characteristics of the riser. In the lumped mass model, the tensions, shear forces, buoyancy, self-weights, and seabed reaction forces at nodal points are considered in order to find the static configuration of the SLWR. The dynamic relaxation method using a viscous damping formulation is applied to the static configuration analysis. Fictitious masses are defined at nodal points using the sum of the largest direct stiffness values of nodal points to ensure the numerical stability. Various case studies were performed according to the bending stiffness and size of the buoyancy module using the dynamic relaxation method. OrcaFlex was employed to validate the accuracy of the developed numerical method.