• Title/Summary/Keyword: Bio-Engineering

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Computer-aided Design and Fabrication of Bio-mimetic Scaffold for Tissue Engineering Using the Triply Periodic Minimal Surface (삼중 주기적 최소곡면을 이용한 조직공학을 위한 생체모사 스캐폴드의 컴퓨터응용 설계 및 제작)

  • Yoo, Dong-Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.7
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    • pp.834-850
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    • 2011

  • In this paper, a novel tissue engineering scaffold design method based on triply periodic minimal surface (TPMS) is proposed. After generating the hexahedral elements for a 3D anatomical shape using the distance field algorithm, the unit cell libraries composed of triply periodic minimal surfaces are mapped into the subdivided hexahedral elements using the shape function widely used in the finite element method. In addition, a heterogeneous implicit solid representation method is introduced to design a 3D (Three-dimensional) bio-mimetic scaffold for tissue engineering from a sequence of computed tomography (CT) medical image data. CT image of a human spine bone is used as the case study for designing a 3D bio-mimetic scaffold model from CT image data.

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Nonlinear stability of bio-inspired composite beams with higher order shear theory

  • Nazira Mohamed;Salwa A. Mohamed;Alaa A. Abdelrhmaan;Mohamed A. Eltaher
    • Steel and Composite Structures
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    • v.46 no.6
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    • pp.759-772
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    • 2023

  • This manuscript presents a comprehensive mathematical model to investigate buckling stability and postbuckling response of bio-inspired composite beams with helicoidal orientations. The higher order shear deformation theory as well as the Timoshenko beam theories are exploited to include the shear influence. The equilibrium nonlinear integro-differential equations of helicoidal composite beams are derived in detail using the energy conservation principle. Differential integral quadrature method (DIQM) is employed to discretize the nonlinear system of differential equations and solve them via the Newton iterative method then obtain the response of helicoidal composite beam. Numerical calculations are carried out to check the validity of the present solution methodology and to quantify the effects of helicoidal rotation angle, elastic foundation constants, beam theories, geometric and material properties on buckling, postbuckling of bio-inspired helicoidal composite beams. The developed model can be employed in design and analysis of curved helicoidal composite beam used in aerospace and naval structures.

  • https://doi.org/10.12989/scs.2023.46.6.759 인용

Modal and Stress Analysis of Spur Gear in DC Motor Gearhead using Finite Element Model

  • Pratama, Pandu Sandi;Supeno, Destiani;Jeong, Seongwon;Park, Cunsook;Woo, Jihee;Lee, Eunsook;Yoon, Woojin;Choi, Wonsik
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2017.04a
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    • pp.17-17
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    • 2017

  • In electric agricultural machine the gearhead is needed to convert the high speed low torque rotation motion generated by DC motor to lower speed high torque motion used by the vehicle. The gearhead consist of several spur gears works as reduction gears. Spur gear have straight tooth and are parallel to the axis of the wheel. Spur gears are the most easily visualized gears that transmit motion between two parallel shafts and easy to produce. The modeling and simulation of spur gears in DC motor gearhead is important to predict the actual motion behavior. A pair of spur gear tooth in action is generally subjected to two types of cyclic stress: contact stress and bending stress including bending fatigue. The stress may not attain their maximum values at the same point of contact fatigue. These types of failure can be minimized by analysis of the problem during the design stage and creating proper tooth surface profile with proper manufacturing methods. To improve its life expectation in this study modal and stress analysis of gearhead is simulated using ansys work bench software based on finite element method (FEM). The modal analysis was done to understand gearhead deformation behaviour when vibration occurs. FEM static stress analysis is also simulated on gearhead to simulate the gear teeth bending stress and contact stress behavior. This methodology serves as an approach for gearhead design evaluation, and the study of gear stress behavior in DC motor gearhead which is needed in the small workshop scale industries.

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