Home / Journals / SDHM / Vol.8, No.4, 2012
  • Open Access

    ARTICLE

    Relaxation of Residual Stress under Fatigue Load Described in Terms of Cyclic-Plastic Deformation Model

    S. Kwofie1
    Structural Durability & Health Monitoring, Vol.8, No.4, pp. 295-306, 2012, DOI:10.32604/sdhm.2012.008.295
    Abstract Fatigue life of components may be enhanced by mechanical surface treatments, such as shot penning, which induce compressive residual stresses in the component's surface. Under cyclic/fatigue loads, however, relaxation of the residual stress may occur thus, reducing the optimum benefit of the surface treatment. For health monitoring / life prediction under such conditions it is important to be able to assess stress relaxation in real-time. However, the phenomenon of cyclic relaxation of residual stress is not well understood and its tracking during component operation is a technical challenge. By means of cyclic plastic deformation model and the Matlab/Simulink Program cyclic… More >

  • Open Access

    ARTICLE

    A Method for the Verification of Structural Integrity of Lower Limbs Prostheses

    C. Colombo1, E.G. Marchesin1, L. Vergani1,2, E. Boccafogli3, G. Verni3
    Structural Durability & Health Monitoring, Vol.8, No.4, pp. 307-328, 2012, DOI:10.32604/sdhm.2012.008.307
    Abstract In this study an experimental device for testing the structural integrity of lower limb (transtibial and transfemoral) prostheses is proposed and studied, in accordance with the ISO 10328 Standard. Aim of the development of this device is to mechanically test these kinds of prostheses, for claiming the compliance with the standard. In the first part of the paper, experimental setup of the laboratory is described for the different kinds of prescribed tests. In the second part, the test case of a transtibial prosthesis for children is proposed. After verifying the compliance with the standard of the studied prosthesis, values recorded… More >

  • Open Access

    ARTICLE

    Rolling Contact Fatigue Damage Detected by Correlation between Experimental and Numerical Analyses

    L. Solazzi1,2, C. Petrogalli1, M. Lancini1
    Structural Durability & Health Monitoring, Vol.8, No.4, pp. 329-340, 2012, DOI:10.32604/sdhm.2012.008.329
    Abstract A study on vibrations related to rolling contact fatigue test bench and a possible way to correlate this mechanical behavior and damage of the specimens is presented. In particular it has been evaluated the possibility to detect and quantify, thanks to vibration analysis, the damage on two discs subjected to rolling contact fatigue in different working conditions. Paper is divided in two parts. In the first part there is a description of test bench and results of its static and modal analyses. Then, some tests were carried out changing working conditions and specimens' parameters and a procedure that allowed both… More >

  • Open Access

    ARTICLE

    On the Structural Response of Elasto/Viscoplastic Materials Subject to Time-Dependent Loadings

    F. De Angelis1
    Structural Durability & Health Monitoring, Vol.8, No.4, pp. 341-358, 2012, DOI:10.32604/sdhm.2012.008.341
    Abstract The influence of different loading rates on the structural response of elasto/viscoplastic materials is illustrated with specific numerical examples. An associated formulation of the evolutive laws in elasto/viscoplasticity is presented within the framework of the generalized standard material model with internal variables. An appropriate solution scheme is applied which is capable to be adopted for different constitutive models. Different loading programs are analyzed by considering different values of the loading rate and of the intrinsic properties of the material. Computational applications and examples are illustrated which describe the rate-dependency of the elasto/viscoplastic material behavior. The significance of the loading program… More >

  • Open Access

    ARTICLE

    Damage Monitoring of Ultrasonically Welded Aluminum / CFRP-Joints during Cyclic Loading via Electrical Resistance Measurements

    F. Balle1, S. Huxhold1, G. Wagner1, D. Eifler1
    Structural Durability & Health Monitoring, Vol.8, No.4, pp. 359-370, 2012, DOI:10.32604/sdhm.2012.008.359
    Abstract Aluminum alloys and carbon fiber reinforced polymers (CFRP) are two important materials for lightweight design and the combination of these dissimilar materials becomes increasingly important. Recent investigations have shown that ultrasonic metal welding is a well suited process to realize aluminum/CFRP-joints.The ultrasonic shear oscillation parallel to the welding zone with a simultaneous welding force perpendicular to the aluminum/CFRP-sheets melts the polymer matrix and squeezes the polymer matrix out of the welding zone. This allows a direct contact between the carbon fibers and the aluminum. Beside monotonic properties the cyclic deformation behavior of these ultrasonically welded aluminum/CFRP-joints is essential. Therefore in… More >

Share Link

WeChat scan