• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.21 no.1
• /
• pp.154-163
• /
• 1997

Thermally-induced deformation in SMC(Sheet Molding Compound) products is analyzed using three dimensional finite element method. Planar fiber orientation, which causes the anisotropic material properties, is calculated through the flow analysis during the compression stage of the mold. Also curing process is analyzed to predict temperature profile which has significant effects on warpage of SMC products. Through the developed procedure, effects of various process conditions such as charge location, mold temperature, fiber contents, and fiber orientations on deformation of final products are studied. and processing strategies are proposed to reduce the warpage and the shrinkage.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.52 no.6
• /
• pp.247-253
• /
• 2003

A novel finite element mesh regeneration method is presented for 3D shape optimization of electromagnetic devices. The method has its theoretical basis in the structural deformation of an elastic body. When the shape of the electromagnetic devices changes during the optimization process, a proper 3D finite element mesh can be easily obtained using the method from the initial mesh. For real engineering problems, the method guarantees a smooth shape with proper mesh quality, and maintains the same mesh topology as the initial mesh. Application of the optimum design of an electromagnetic shielding plate shows the effectiveness of the presented method.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.22 no.1
• /
• pp.111-120
• /
• 1998

This paper is the first one of two-parted research efforts focusing on the modeling of rubber pad forming process. The rubber pad, driven by the pressurized fluid during the forming process, pushes the sheet metal to solid tool half and forms a part to final shape. In this part of the paper, a numerical procedure for the FE analysis of the rubber pad deformation is presented. The developed three-dimensional FE model is based on the total Lagrangian description of rubber maerial characterized by nearly incompressible hyper-elastic behavior under a large deformation assumption. Validity of the model as well as effects of different algorithms corresponding to incompresibility constraints and time integration methods on numerical solution responses are also demonstrated.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.15 no.2
• /
• pp.523-536
• /
• 1991

This dissertation analyzes the running mechanism of flexible and thin tape above rotating head through the numerical simulation and the experiment. The scope of analysis is confined to the phenomena of two dimensional elasto hydrodynamic lubrication between the protruded bump on a rotating cylinder and the running tape. This model is based on the elastic deformation equation of plate and shell and Reynolds equation. Finite difference method is employed as a numerical technique to calculate (1) the distribution of pressure between the running tape and rotating bump and (2) the vertical deformation of elastic thin tape over he rotating bump under hydrodynamic pressure. In numerical analyses, the effects of bump size on flying characteristics of the tape were evaluated and examined considering the influence of tension and stiffness of tape.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.10 no.3
• /
• pp.143-150
• /
• 2002

The characteristics of rubber cup seal is highly nonlinear due to the nature of the material's non-linearity and large deformation with frictional contact. And the performance of sealing in master cylinders of automobile is one of the most important factors which affects the safety of drivers. The effects of various shape of the primary cup seal in clutch master cylinder was investigated to reduce oil leakage and to obtain a long reliable life. Deformation and distribution of stresses on the primary cup seal against hydraulic oil pressure were analyzed with changing design parameters such as depth and radius in cup-seal. The obtained results indicate that the depth of cup seal plays a major role on deformation resulting in the sealing force to the wall of clutch master cylinder.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.11
• /
• pp.2466-2473
• /
• 2002

In twin roll strip casting process, the design of casting roll is the most important equipment for producing strip. Analyses of heat transfer and deformation for the casting roll are carried out by using the finite element program, ANSYS. Both the elastic deformation and the elasto-plastic deformation under a thermal load are considered in the analysis. Optimization to minimize the volume of roll is performed under the various thermal loads such as the heat flux and the roll speed. Design variables are defined by diameters and positions of the cooling hole in the roll , Although the thermal load remarkably varies, the design variables and objective function are found to be consistent.

• Journal of KSNVE
• /
• v.6 no.3
• /
• pp.287-296
• /
• 1996

A virtual work form of flexible multibody dynamic formulation with rotary inertia has been derived. For the analysis of large flexible multibody systems, deformation modal coordinates have been employed to represent coupled motion between gross and vibrational motion. For the efficient evaluation of the entries in the mass matrix, a flexible body has been treated as a collection of mass points. The rotary inertia was generated from the consistent mass matrix in a finite element model. Deformation mode shapes were obtained from finite element analysis. Bending and twisting vibration analyses of a cantilever have been carried out to see rotary inertia effects. A space flexible robot simulation has been also carried out to show effectiveness of the proposed formulation. This formulation is effective to the model that consists of beam, plate, or shell element that contains rotational degree of freedom at the nodal point. It is also effective to the flexible body model to which a large lumped rotary inertia is attached.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.780-785
• /
• 2007

Accurate and fast haptic simulations of deformable objects are desired in many applications such as medical virtual reality. In haptic interactions with a coarse model, the number of nodes near the haptic interaction region is too few to generate detailed deformation. Thus, local refinement techniques need to be developed. Many approaches have employed purely geometric subdivision schemes, but they are not proper in describing the deformation behavior of deformable objects. This paper presents a continuum mechanics-based finite element adaptive method to perform haptic interaction with a deformable object. This method superimposes a local fine mesh upon a global coarse model, which consists of the entire deformable object. The local mesh and the global mesh are coupled by the s-version finite element method (s-FEM), which is generally used to enhance accurate solutions near the target points even more. The s-FEM can demonstrate a reliable deformation to users in real-time.

• Steel and Composite Structures
• /
• v.19 no.4
• /
• pp.789-809
• /
• 2015

This paper presents experimental and numerical studies into the structural behavior of a high performance corbel type composite connection adopted in Raffles City of Hangzhou, China. Physical tests under both monotonic and quasi-static cyclic loads were conducted to investigate the load carrying capacities and deformation characteristics of this new type of composite connection. A variety of structural responses are examined in detail, including load-deformation characteristics, the development of sectional direct and shear strains, and the history of cumulative plastic deformation and energy. A three-dimensional finite element model built up with solid elements was also proposed for the verification against test results. The studies demonstrate the high rigidity, strength and rotation capacities of the corbel type composite connections, and give detailed structural understanding for engineering design and practice. Structural engineers are encouraged to adopt the proposed corbel type composite connections in mega high-rise buildings to achieve an economical and buildable and architectural friendly engineering solution.

• Steel and Composite Structures
• /
• v.10 no.6
• /
• pp.489-500
• /
• 2010

The rigid connections of I-beams to Rectangular Hollow Sections (RHS) in steel structures usually behave as semi-rigid connection. This behavior is directly related to the column face deformation. The deformation in the wall of RHS column in the connection zone causes a relative rotation between beam end and column axis, which consequently reduces the rigidity of beam-column connection. In the present paper, the percentages of connection rigidity reduction for serviceability conditions are evaluated by using the finite element analysis. Such percentages for RHS columns without internal stiffeners are considerable, and can be calculated from presented graphs.