Yazar "Karaagac, Celalettin" seçeneğine göre listele

Listeleniyor 1 - 6 / 6
  • Küçük Resim Yok
    Öğe
    Crack effects on the in-plane static and dynamic stabilities of a curved beam with an edge crack
    (Academic Press Ltd- Elsevier Science Ltd, 2011) Karaagac, Celalettin; Ozturk, Hasan; Sabuncu, Mustafa
    The effects of a single-edge crack and its locations on the buckling loads, natural frequencies and dynamic stability of circular curved beams are investigated numerically using the finite element method, based on energy approach. This study consists of three stages, namely static stability (buckling) analysis, vibration analysis and dynamic stability analysis. The governing matrix equations are derived from the standard and cracked curved beam elements combined with the local flexibility concept. Approximation for the displacements using coupled interpolations based on the constant-strain, linear-curvature element (SC) has yielded results with reasonable accuracy. The numerical results obtained from the present finite element model are found to be in good agreement with those, both experimental and analytic, of other researchers in the existing literature. Results show that the reductions in buckling load and natural frequency depend not only on the crack depth and crack position, but also on the related mode shape. Analyses also show that the crack effect on the dynamic stability of the considered curved beam is quite limited. (C) 2010 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Effects of an edge crack on the free vibration and lateral buckling of a cantilever laminated composite slender beam
    (Sage Publications Ltd, 2013) Karaagac, Celalettin; Ozturk, Hasan; Sabuncu, Mustafa
    The objective of this paper is to investigate the effects of laminate scheme, crack ratio (a/h) and crack position (L-1/L) on the free vibration and lateral buckling of a cantilever slender rectangular beam such as an airplane wing or a wind turbine blade with a single edge crack. The local flexibility approach is adopted to model the crack, based on linear fracture mechanics and the Castigliano theorem. The governing matrix equations for free vibration and buckling load are derived from the standard beam element and cracked beam element combined with the local flexibility concept. The results are obtained numerically using the finite element method, based on the energy approach and are given for crack ratios up to 0.5 at crack positions up to 0.9 ratio. Polynomial approximation for displacements gives results with reasonable accuracy.
  • Küçük Resim Yok
    Öğe
    Fracture and fatigue analysis of an agitator shaft with a circumferential notch
    (Pergamon-Elsevier Science Ltd, 2006) Karaagac, Celalettin; Toygar, M. Evren
    This paper is concerned with the fracture analysis of an agitator shaft of a large vessel and predicting its high cycle fatigue life. The agitator shaft has a circumferential notch around it and is subjected to remote bending and torque created by the mixing operation. The problem is comprised (i) the analyses of the bending force and torque acting on the agitator by using the analytical method, (ii) calculation of stress intensity factors under mode I and III loading conditions by using finite element method and, (iii) fatigue analysis of the agitator shaft failed in service. An agitator model is set up and data obtained from the agitator are processed to make more realistic approximations for bending forces, since they form a base for stress analysis, in which mode I stress intensity factors are evaluated. Mode I stress intensity factors obtained by finite element analysis are compared with the results provided by using the body force method. (c) 2006 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Free vibration and lateral buckling of a cantilever slender beam with an edge crack: Experimental and numerical studies
    (Academic Press Ltd- Elsevier Science Ltd, 2009) Karaagac, Celalettin; Ozturk, Hasan; Sabuncu, Mustafa
    The effects of crack ratios and positions on the fundamental frequencies and buckling loads of slender cantilever Euler beams with a single-edge crack are investigated both experimentally and numerically using the finite element method. based on energy approach. The governing matrix equations are derived from the standard and cracked beam elements combined with the local flexibility concept. The experiments are conducted using specimens having edge cracks of different depths at different positions to validate the numerical results obtained. The numerical results are shown to be in good agreement with the experimental results for the considered crack ratios. (C) 2009 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Free vibration and lateral buckling of a cantilever slender beam with an edge crack: Experimental and numerical studies
    (Academic Press Ltd- Elsevier Science Ltd, 2009) Karaagac, Celalettin; Ozturk, Hasan; Sabuncu, Mustafa
    The effects of crack ratios and positions on the fundamental frequencies and buckling loads of slender cantilever Euler beams with a single-edge crack are investigated both experimentally and numerically using the finite element method. based on energy approach. The governing matrix equations are derived from the standard and cracked beam elements combined with the local flexibility concept. The experiments are conducted using specimens having edge cracks of different depths at different positions to validate the numerical results obtained. The numerical results are shown to be in good agreement with the experimental results for the considered crack ratios. (C) 2009 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Lateral dynamic stability analysis of a cantilever laminated composite beam with an elastic support
    (World Scientific Publ Co Pte Ltd, 2007) Karaagac, Celalettin; Ozturk, Hasan; Sabuncu, Mustafa
    In this paper, static and dynamic stabilities of a cantilever laminated composite beam, having a linear translation spring as elastic support whose position is changeable from the free end to midspan of the beam, subjected to periodic vertical end loading, are examined. The beam is assumed to be an Euler beam and the finite element model used can accommodate symmetric and antisymmetric lay-ups. Solutions referred to as combination resonance are investigated for the dynamic stability analysis. The effects of length-to-thickness ratio, the variation of cross-section in one direction, orientation angle, static and dynamic load parameters, stiffness and position of the elastic support on stability are examined.