• Proceedings of the KSME Conference
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• 2005.11a
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• pp.141.2-141.2
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• 2005

• Composites Research
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• v.30 no.5
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• pp.297-302
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• 2017

Finite element analysis of T-beam laminate structure under bending-torsional loading was conducted to prevent the delamination which is the major failure behavior on laminated composites. Three-dimensional preform, which is that fabric is braided through thickness direction, is suggested from the laminate analysis. The analysis aimed to optimize the fiber ratio in laminated composites. After it is suggested that guideline for design of T-beam structure using commercial software ANSYS Composites PrePost. The results show that strength of T-beam structure is increased 21.6% when the fiber density along with beam length direction is two times bigger than transverse direction. It is expected that development of high strength T-beam structure using designed three-dimensional preform.

• Journal of the KSME
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• v.34 no.5
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• pp.372-383
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• 1994

복합재료의 피로특성과 해석방법에 대하여 간략하게 살펴보았다. 복합재료의 피로현상에 대한 이해의 폭이 넓어짐에 따라 앞에서 소개한 방법외에 파단모드별 연구, 역학에 기초를 둔 해석법, 유한요소법의 적용, 혼성복합재료(hybrid composites)의 피로수명 예측 등의 다양한 연구가 진 행중이나, 아직 정립된 피로수명 예측식은 없다고 말할 수 있다. 재료의 손상을 나타내는 매개 변수로서 강성변화의 유용성이 밝혀진 상태이므로 앞으로 이를 이용하여 실제의 현상을 표현할 수 있는 손상함수의 구성과 피로수명 예측에 관한 연구가 수행되어야 한다.

• Composites Research
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• v.29 no.6
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• pp.347-352
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• 2016

This work presents the free vibration characteristics of laminated composite corrugated rectangular plates using the analytical method. Because it is very difficult to determine its mechanical behavior of 3-dimensional corrugated structures analytically, the equivalent homogenization model is adapted to investigate the overall mechanical behavior of corrugated structures. The corrugated element can be homogenized as an orthotropic material. Both the effective extensional and flexural stiffness of this homogenized equivalent orthotropic material are considered in the analysis. The present analytical results are validated by those obtained from 3D finite element analysis based on shell elements. The natural frequencies and global vibration mode shapes obtained from present analytical and finite element analysis are presented. Some numerical results are presented to check the effect of the geometric properties.

• Composites Research
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• v.30 no.6
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• pp.338-342
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• 2017

In this paper, evaluation method of structural integrity of cylindrical composite lattice structures was conducted. A finite element analysis was used to evaluate the structural integrity of composite lattice structures. In order to verify the optimal finite element in the evaluation of the structural integrity, finite element models for cylindrical composite lattice structure were generated using beam, shell and solid elements. The results of the finite element analyses with the shell and solid element models showed a good agreement. However, considerable differences were found between the beam element model and the shell and solid models. This occurred because the beam element does not take into account the degradation of the mechanical properties of the non-intersection parts of cylindrical composite lattice structures. It was found that the finite element analysis of evaluation of structural integrity for cylindrical composite lattice structures have to use solid element.

• Composites Research
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• v.25 no.5
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• pp.136-140
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• 2012

This paper describes the bone healing process of fractured long bones such as a tibia applied by composite IM rods using finite element analysis. To simulated tissue differentiation process mechano-regulation theory with a deviatoric strain was implemented and a user's subroutine programmed by a Python code for an iterative calculation was used. To broadly find the appropriate rod modulus for healing bone fractures, composite IM rods were analyzed considering the stacking sequence. To compare mechanical stimulation at fracture gap, two kinds of initial loading conditions were applied. As a result, it was found that the initial loading condition was the most sensitive factor for the healing performance. In case a composite IM rod made of a plain weave carbon fiber/epoxy (WSN3k) had a stacking sequence of $[{\pm}45]_{nT}$, the healing efficiency was the most effective under a initial load of 10%BW.

• Composites Research
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• v.33 no.4
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• pp.220-227
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• 2020

When curing the composite, the fibers have little thermal deformation, but the resin changes its properties with time and temperature, which leads to residual stress in the product. Residual stress is caused by the difference in the coefficient of thermal expansion of the fibers and resin during the curing process and the chemical shrinkage of the resin. This difference causes thermal deformation such as spring-in and warpage. Thermal deformation of composite structure is important issue on quality of product, and it should be considered in manufacturing process. In this study, a subroutine was developed to predict thermal deformation by applying 3-D viscoelastic model. The finite element analysis was verified by comparing the results of the plate analysis of the 2-D viscoelastic model. Spring-in of L-shaped structure was predicted and analyzed by applying the 3-D viscoelastic model.

• Composites Research
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• v.28 no.2
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• pp.65-69
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• 2015

This study dealt with dynamic characteristics by real car crash simulation of composite support structures for road facilities. The effects of different material properties of composites for various car crash speeds are studied using the LS-DYNA finite element program for this study. In this study, the existing finite element analysis of steel support structures using the LS-DYNA program is further extended to study dynamic behaviors of the support structures made of various composite materials. Based on the passenger safety assessment, the numerical results for various parameters are verified by comparing different models with internal energy occurred in the support and car.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.3
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• pp.92-98
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• 1998

This paper presents three boundary techniques which are useful for FEM analysis of composite laminates: 1) a rotational symmetric boundary technique . 2) a quasi three-dimensional boundary technique and 3) a contact boundary technique. The use of the rotational symmetric boundary technique is possible for a smaller FEM model. With the use of the quasi three-dimensional boundary tecnique. quasi three dimensional analysis of composite laminates can be performed on the conventional 3-D FEM program These techniques can readily be adopted to FEM programs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.56-56
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• 2004

섬유강화 복합재료는 응용범위가 산업계 전반으로 빠르게 확대되고 있다. 개발 초기에는 하중을 감당하지 않는 이차 구조물에 주로 사용되어 왔으나, 점차 산업 전반의 I차 구조물(Primary Structure)에 쓰이는 등, 그 사용범위가 넓어지고 있으며, 취약한 두께방향 물성 향상의 필요성을 충족시키기 위해 다축경편(MWK) 복합재료에 대한 연구가 진행되고 있다. 본 논문에서는 다축경편(MWK) 복합재료의 기계적 체결부에 관한 응력해석을 연구하였다.(중략)