Home / Journals / SL / Vol.3, No.3, 2010
Journal Menu
  • Open Access

    ARTICLE

    Hysteretic Behaviour of Square Tubular T-joint With and Without Collar-Plate Reinforcement under Axial Cyclic Loading

    Y.B. Shao1, S.P. Chiew2, Y. Chen1, S.T. Lie2
    Structural Longevity, Vol.3, No.3, pp. 171-189, 2010, DOI:10.3970/sl.2010.003.171
    Abstract For a square tubular T-joint under axial loading, failure occurs easily along the weld toe because high stress concentration exists in this region. This phenomenon can be used to explain why brittle fracture is dominant when the joint is subjected to cyclic loading, such as faigue loading or earthquake loading. To improve the seismic resistance of a square tubular joint, collar plate can be used to reinforce the joint connection. However, the aseismic behaviour of the collarplate reinoforced tubular joint must be assessed because only the increase of the load carrying capacity can not guarantee the capacity of energy dissipation… More >

  • Open Access

    ARTICLE

    Fatigue Properties of Nitrided Alloy 718 at Elevated Temperature

    N. Kawagoishi1, A. Ohkubo2, S. Yoshimi3, K. Yamane4, K. Morino5
    Structural Longevity, Vol.3, No.3, pp. 191-199, 2010, DOI:10.3970/sl.2010.003.191
    Abstract Rotating bending fatigue tests were carried out using a radical nitrided nickel base superalloy, Alloy 718, at 500 ℃, to investigate the effect of radical nitriding on the initiation and propagation behavior of a fatigue crack at elevated temperature. The nitriding was conducted at 500 ℃ for 12h which was relatively low temperature compared with other nitriding technologies. Compound layer was formed on the specimen surface with the thickness of about 4µm. Hardness of the base alloy was hardly affected by nitriding. When stress levels were high, a crack initiated from the specimen surface in the aged alloy, and the… More >

  • Open Access

    ARTICLE

    Effects of Reverted Austenite and Hardness on Fatigue Properties of Shot Peened Maraging Steel in Long Life Region

    T. Nagano1, M. Moriyama2,3, N. Kawagoishi4, Y. Kobayashi4
    Structural Longevity, Vol.3, No.3, pp. 201-211, 2010, DOI:10.3970/sl.2010.003.201
    Abstract In the present study, rotating bending fatigue tests up to 108 cycles were carried out to investigate the effects of hardness of base steel and shot and reverted austenite, γ, on the fatigue strength and the fracture mechanism in wide range of fatigue life of shot peened 3.5GPa-grade maraging steel. By shot peening, hardening and compressive residual stress were yielded in the surface layer of specimen, causing increase in fatigue strength in the wide region of fatigue life. The SN curves showed duplex SN properties because of the transition of fracture origin from the specimen surface… More >

  • Open Access

    ARTICLE

    Evaluation of Thermal-damages in Tube-like Structures using Ultrasonic Guided Waves

    Younho Cho1, Weibin Li1, Bin Yang1
    Structural Longevity, Vol.3, No.3, pp. 213-219, 2010, DOI:10.3970/sl.2010.003.213
    Abstract This paper aims at an experimental method for detecting thermal-damages in a tube-like structure using acoustic nonlinear parameter of ultrasonic guided waves. The material nonlinearity of aluminum pipe specimens, which have been subjected to different heat-loading cycles, is measured to characterize the microdamages. Flexible Polyvinylidene Fluoride (PVDF) comb transducers are used to generate and receive the fundamental and second harmonic waves. The amplitude of the second harmonic wave is extracted from the Fast Fourier Transform (FFT) spectrum of a received signal. The measured relative nonlinear parameter increases monotonically as a function of the propagation distance, and the relative nonlinear parameter… More >

  • Open Access

    ARTICLE

    Damage Detection in z-Fiber Reinforced, Co-Cured Composite Pi-Joint Using Pitch-Catch Ultrasonic Analysis and Scanning Laser Vibrometry

    Hitesh Kapoor1, James L. Blackshire2, Som R. Soni3
    Structural Longevity, Vol.3, No.3, pp. 221-238, 2010, DOI:10.3970/sl.2010.003.221
    Abstract Damage detection in constrained geometry structures like z-pinned, co-cured composite pi-joints is established using pitch-catch ultrasound and scanning laser vibrometry measurements. Ultrasonic pitch-catch measurements consisted of a network of PZT (Lead Zirconate Titanate) sensors placed on the specimen and sensing Lamb waves at each sensor location, where measurements were taken at symmetric top and bottom sensor locations for healthy and damaged pijoint specimens. Results showed the presence of fatigue-induced bend damage of the joint as a reduced peak-to-peak amplitude response across the joint. Scanning laser vibrometry measurements were used to study the propagation of Lamb waves within the narrow, constrained… More >

Share Link

WeChat scan