• Journal of KSNVE
• /
• v.10 no.1
• /
• pp.97-106
• /
• 2000

The dynamic behavior of crankshaft-bearing system in scroll compressor has been investigated using the combined methodologies of finite elements and transfer matrices. The finite element formulation is proposed including the field element for a shaft section and the point element at balancer weight locations, bearing locations, etc., whereas the conventional method is used with the elements. The Houbolt method is used to consider the time march for the integration of the system equations. The linear stiffness and damping coefficients are calculated for a finite cylindrical fluid-film bearing by solving the Reynolds equation, using finite difference method. The orbital response of crankshaft supported on the linear bearing model is obtained, considering balancer weights of motor rotor. And, the steady state displacement of crankshaft are compared with a variation in balancer weight. The loci of crankshaft at bearing locations are composed of the synchronous whirl component and the non-synchronous whirl component.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.21 no.4
• /
• pp.375-382
• /
• 2008

The particular integral formulation for two(2D) and three(3D) dimensional inelastic transient dynamic stress analysis is presented. The elastostatic equation is used for the complementary solution. Using the concept of global shape function, the particular integrals for displacement and traction rates are obtained to approximate acceleration of the inhomogeneous equation. The Houbolt time integration scheme is used for the time-marching process. The Newton-Raphson algorithm for plastic multiplier is used to solve the system equation. Numerical results of four example problems are given to demonstrate the validity and accuracy of the present formulation.

• 한국기계연구소 소보
• /
• s.17
• /
• pp.99-109
• /
• 1987

Mechanisms with fully elastic members must consider both inertial forces due to the rigid motion of mechanisms and due to the elastic vibration of links. The main objectives of the kineto-elasto static and dynamic analyses are to calculate the quasi-static and the time-domain responses, respectively. An iterative transfer matrix method is used for a four-bar, fully elastic linked mechanism. Houbolt direct integration scheme is incorporated for the inertial effects due to the elastic link vibration. The analytical results are compared with the experimental responses and both responses show in good agreement.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.29 no.2 s.233
• /
• pp.293-302
• /
• 2005

In this paper, the thick-walled laminated, orthotropic as well as bimaterial, composite hollow spheres under impact pressure are analyzed in detail by using the semi-discrete finite element method with the Houbolt time-integration scheme which results in unconditionally stable transient numerical results. Numerical results are obtained by using the self-constructed spherically symmetric (one-dimensional) and axially symmetric (two-dimensional) finite element programs, and compared with the previous solutions by other researchers, being shown some of which are incorrect. The finite element package Nastran is also adopted for numerical comparison.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.20 no.5
• /
• pp.521-532
• /
• 2007

Elastic wave propagations in the semi-infinite transversely isotropic cylinder under various kinds of longitudinal impact loads are analyzed using the axisymmetric finite element method and Houbolt time-integration scheme. For which the finite element program is newly constructed and verified through the comparison of present numerical results with those by other researchers. E-type glass-epoxy composite cylinders with different fiber volume fractions are adopted and studied in detail with dynamic responses of the isotropic cylinder. Three dimensional wave motions are given in graphic form to show the realistic view of the wave propagation. Nondimensionalized dynamic characteristic variables which relate the size of finite element mesh, the time step, and the wave speed are presented for obtaining accurate and stable numerical results.