• 제목/요약/키워드: contact of crack faces

검색결과 2건 처리시간 0.018초

A new approach for finite element analysis of delaminated composite beam, allowing for fast and simple change of geometric characteristics of the delaminated area

  • Perel, Victor Y.
    • Structural Engineering and Mechanics
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    • 제25권5호
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    • pp.501-518
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    • 2007
  • In this work, a new approach is developed for dynamic analysis of a composite beam with an interply crack, based on finite element solution of partial differential equations with the use of the COMSOL Multiphysics package, allowing for fast and simple change of geometric characteristics of the delaminated area. The use of COMSOL Multiphysics package facilitates automatic mesh generation, which is needed if the problem has to be solved many times with different crack lengths. In the model, a physically impossible interpenetration of the crack faces is prevented by imposing a special constraint, leading to taking account of a force of contact interaction of the crack faces and to nonlinearity of the formulated boundary value problem. The model is based on the first order shear deformation theory, i.e., the longitudinal displacement is assumed to vary linearly through the beam's thickness. The shear deformation and rotary inertia terms are included into the formulation, to achieve better accuracy. Nonlinear partial differential equations of motion with boundary conditions are developed and written in the format acceptable by the COMSOL Multiphysics package. An example problem of a clamped-free beam with a piezoelectric actuator is considered, and its finite element solution is obtained. A noticeable difference of forced vibrations of the delaminated and undelaminated beams due to the contact interaction of the crack's faces is predicted by the developed model.

환상구열을 갖는 축의 비틀림피로 구열성장거동에 관한 기초연구 (A study on the torsional fatigue crack propagation behavior on the shaft with circumferential crack)

  • 김복기;최용식
    • 오토저널
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    • 제13권6호
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    • pp.101-108
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    • 1991
  • During torsional fatigue of externally cracked cylindrical specimen, crack face rubbing may occur. At this time, normal contact forces arise when shear displacements cause the crack faces to be wedged open due to mismatch of the fracture surface asperities. These normal forces, in turn, generate friction force which act in opposition to the applied shear stresses and reduce the effective stress intensity factor. The premise of the proposed work is that friction and wedging can be studied by measuring the shear and normal displacement across the crack mouth. We have measured the crack mouth compliance using the new biaxial extensometer.

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