The Experts below are selected from a list of 20520 Experts worldwide ranked by ideXlab platform

Kyoo Kim - One of the best experts on this subject based on the ideXlab platform.

Wan Keun Kim - One of the best experts on this subject based on the ideXlab platform.

Xiang Zhang - One of the best experts on this subject based on the ideXlab platform.

  • fatigue Crack propagation behaviour in wire arc additive manufactured ti 6al 4v effects of microstructure and residual stress
    Materials & Design, 2016
    Co-Authors: Jikui Zhang, Xueyuan Wang, Sanjooram Paddea, Xiang Zhang
    Abstract:

    Abstract Fatigue Crack propagation tests of Ti‐6Al‐4V fabricated by the Wire+Arc Additive Manufacturing (WAAM) process are analysed. Crack growth rate and trajectory are examined before and after the Crack tip crossing an interface between the WAAM and wrought alloys. The study has focused on the microstructure and residual stress effect. First, the differences in Crack growth rate and path between WAAM and wrought alloys are attributed to their different microstructure; the equiaxed wrought alloy has straight Crack path, whereas the WAAM lamellar structure causes tortuous Crack path resulting in lower Crack growth rate. Second, based on measured residual stress profile in the as-built WAAM piece, retained residual stress in the much smaller compact tension specimens and its effect on Crack growth rate are calculated by the finite element method. Numerical simulation shows considerable residual stress in the test specimen and the stress magnitude depends on the Initial Crack location and propagation direction in relation to the WAAM-wrought interface. Residual stress is released immediately if the Initial Crack is in the wrought substrate; hence it has little effect. In contrast, when Crack grows from WAAM to wrought, residual stress is retained resulting in higher stress intensity factor; hence greater Crack growth rate.

Christian Berggreen - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Initial Debond Crack Location on the Face/core Debond Fracture Toughness
    EPJ Web of Conferences, 2010
    Co-Authors: A. Quispitupa Yupa, Christian Berggreen
    Abstract:

    This paper studies the effect of Initial Crack location on the face/core debond fracture toughness under different mixed mode loading conditions. The mixed mode loading at the Crack tip is defined in terms of the mode-mixity. In order to achieve the desired Initial debond Crack location, a pre-Cracking technique is developed, where the mode-mixity, number of cycles, Crack increment and load level are accurately controlled. Results show that the debond fracture resistance of foam-cored sandwich specimens depends on parameters such as loading condition (mode-mixity), core and face properties, as well as Initial debond Crack location. Lower fracture toughness values were measured for specimens with the Initial Crack location in the face laminate.

  • effect of Initial debond Crack location on the face core debond fracture toughness
    14th International Conference on Experimental Mechanics, 2010
    Co-Authors: Quispitupa A Yupa, Christian Berggreen
    Abstract:

    This paper studies the effect of Initial Crack location on the face/core debond fracture toughness under different mixed mode loading conditions. The mixed mode loading at the Crack tip is defined in terms of the mode-mixity. In order to achieve the desired Initial debond Crack location, a pre-Cracking technique is developed, where the mode-mixity, number of cycles, Crack increment and load level are accurately controlled. Results show that the debond fracture resistance of foam-cored sandwich specimens depends on parameters such as loading condition (mode-mixity), core and face properties, as well as Initial debond Crack location. Lower fracture toughness values were measured for specimens with the Initial Crack location in the face laminate.

Jaime Domínguez - One of the best experts on this subject based on the ideXlab platform.

  • analysis of fretting fatigue Initial Crack path in al7075 t651 using cylindrical contact
    Tribology International, 2017
    Co-Authors: J. Vázquez, Carlos Navarro, Jaime Domínguez
    Abstract:

    Abstract This paper analyses the Initial Crack path in a fretting fatigue test of Al7075-T651 alloy with a cylindrical contact and compares the capability of some multiaxial fatigue criteria to predict the Crack initiation path. The experimental Crack initiation paths obtained in the tests are optically measured along the fracture surface using a focus variation technique. The Fatemi-Socie (FS) and Smith-Watson-Topper (SWT) multiaxial fatigue parameters obtained from an analytical model, allow us to determine the controlling parameters of the Crack initiation process observed in the tests and to estimate the Crack path during the early stage of the Crack growth.

  • Analysis of Initial Crack path in fretting fatigue
    Frattura ed Integrità Strutturale, 2016
    Co-Authors: J. Vázquez, Carlos Navarro, S. Astorga, Jaime Domínguez
    Abstract:

    The Initial Crack path is analysed in a fretting fatigue test with cylindrical contact, where there is a stress gradient and a multiaxial and non-proportional stress state. For this, a cylindrical pad is pressed, with a constant normal load, N, against a dog-bone type fatigue test specimen. Then, the test specimen is subjected to a cyclic axial stress, ?. Due to the cyclical axial stress, the assembly used and the friction between the contact pair, a tangential cyclic load Q is generated. In these tests, both components are made of Al7075-T651 alloy. The Crack initiation path along the fracture surface is optically measured using a focus variation technique. The contact stress/strain fields obtained analytically, in junction with the Fatemi-Socie (FS) and Smith-Watson- Topper (SWT) multiaxial fatigue parameters, allow us to determine the controlling parameters of the Crack initiation process observed in the tests and to estimate the Crack path during the early stage of the Crack growth.