The Experts below are selected from a list of 15477 Experts worldwide ranked by ideXlab platform

Yong Peng - One of the best experts on this subject based on the ideXlab platform.

  • finite element modeling of crash test behavior for windshield laminated glass
    International Journal of Impact Engineering, 2013
    Co-Authors: Yong Peng, Jikuang Yang, Caroline Deck, Remy Willinger
    Abstract:

    The objective of the present study is to investigate the mechanical behavior of windshield laminated glass in the case of a pedestrian's head impact. Windshield FE models were set up using different combinations for the modeling of glass and PVB, with various connection types and two mesh sizes (5 mm and 10 mm). Each windshield model was impacted with a standard adult headform impactor in an LS-DYNA simulation environment, and the results were compared with the experimental data reported in the literature. The results indicated that the behavior of the windshield model with a double-layered shell of glass and PVB and a tied element connection support test results from previous studies. Furthermore, the influence of glass Fracture Stress on the same windshield model was investigated, and the cracked area and the peak value of the headform's linear acceleration were determined by the Critical Fracture Stress. It was observed that a 50-MPa Fracture Stress in the glass best p!

Akihiko Nagasaka - One of the best experts on this subject based on the ideXlab platform.

  • pre strain effects on Critical Stress and hydrogen content for hydrogen induced quasi cleavage Fracture in a trip aided bainitic ferrite steel martensitic transformation matrix damage and strain aging
    International Journal of Hydrogen Energy, 2020
    Co-Authors: Bakuya Kumai, Tomohiko Hojo, Motomichi Koyama, Eiji Akiyama, Hiroyuki Waki, Akihiko Nagasaka
    Abstract:

    Abstract In this study, we characterized the details of the pre-strain effects on the microstructure, deformation/Fracture behavior, and hydrogen content, with respect to the true Fracture strength in the TRIP-aided bainitic ferrite steel. Three types of hydrogen embrittlement behavior were distinguished, based on pre-strain and hydrogen content. Pre-strain reduces the fraction of retained austenite, which in turn decreases the hydrogen embrittlement susceptibility when the hydrogen content is low. However, further pre-straining increases dislocation density, which has three main effects: an increase in hydrogen content, work hardening, and strain-age hardening. The increase in the hydrogen content that exceeds 4 mass ppm has been found to decrease the true Fracture strength from approximately 1.5 to 1.2 GPa. The work hardening and strain-age hardening were found to increase until the Critical Fracture Stress was achieved with respect to the strain; this led to a reduction in the elongation, particularly when the hydrogen content was high.

Bakuya Kumai - One of the best experts on this subject based on the ideXlab platform.

  • pre strain effects on Critical Stress and hydrogen content for hydrogen induced quasi cleavage Fracture in a trip aided bainitic ferrite steel martensitic transformation matrix damage and strain aging
    International Journal of Hydrogen Energy, 2020
    Co-Authors: Bakuya Kumai, Tomohiko Hojo, Motomichi Koyama, Eiji Akiyama, Hiroyuki Waki, Akihiko Nagasaka
    Abstract:

    Abstract In this study, we characterized the details of the pre-strain effects on the microstructure, deformation/Fracture behavior, and hydrogen content, with respect to the true Fracture strength in the TRIP-aided bainitic ferrite steel. Three types of hydrogen embrittlement behavior were distinguished, based on pre-strain and hydrogen content. Pre-strain reduces the fraction of retained austenite, which in turn decreases the hydrogen embrittlement susceptibility when the hydrogen content is low. However, further pre-straining increases dislocation density, which has three main effects: an increase in hydrogen content, work hardening, and strain-age hardening. The increase in the hydrogen content that exceeds 4 mass ppm has been found to decrease the true Fracture strength from approximately 1.5 to 1.2 GPa. The work hardening and strain-age hardening were found to increase until the Critical Fracture Stress was achieved with respect to the strain; this led to a reduction in the elongation, particularly when the hydrogen content was high.

H Di - One of the best experts on this subject based on the ideXlab platform.

  • Effect of microstructure on the crack propagation behavior of microalloyed 560 MPa (X80) strip during ultra-fast cooling
    Materials Science and Engineering A, 2016
    Co-Authors: Jian Zhao, G Yuan, W Hu, J. Kang, Xiaodong Wang, H Di
    Abstract:

    A novel thermo-mechanical controlled processing (TMCP) involving ultra-fast cooling (UFC) was used to process microalloyed 560 MPa (X80) strip with Critical thickness of 22 mm. The microstructure and mechanical properties including tensile, Charpy v-notch impact toughness, and drop weight tear test (DWTT) properties were studied, with particular focus on the effect of microstructure on Fracture and crack propagation behavior during DWTT test. The study underscores that the processed strip comprising of acicular ferrite (AF), bainitic ferrite (BF), together with finely distributed martensite/austenite (M/A) constituent provided excellent combination of strength, toughness and crack arrest property. The yield strength (618 MPa), tensile strength (752 MPa), and low-temperature toughness (upper shelf energy of 302 J, transition temperature of -74 °C) as well as DWTT shear area (100%) met the requirements of API SPEC 5L. The predominantly AF microstructure with small-size M/A constituent improved the low-temperature toughness by increasing the Critical Fracture Stress and increased the ability to hinder crack propagation during Charpy test. The AF and finely distributed M/A constituent effectively deflected the crack propagation during DWTT indicating excellent crack arresting property of pipeline strip. It is the cooling schedule of UFC that was responsible for decreasing the effective grain size and increasing the mechanical properties.

Gao Longyang - One of the best experts on this subject based on the ideXlab platform.

  • Study on the long-term behaviour of glass fibre in the tensile Stress field
    Ceramics International, 2019
    Co-Authors: Dapeng Wang, Qingzhao Wang, Wang Zhiming, Huanying Jiang, Zhang Zhao, Liu Peng, Xu Chao, Gao Longyang
    Abstract:

    Abstract Glass fibre is a random network structure composed of [SiO4] tetrahedra. The structure contains a large number of defects, which act as crack initiation points. Under tensile Stress, cracks undergo crack initiation, stable propagation, failure propagation, and Fracture, and the Stress that begins after unstable propagation is called the Critical Fracture Stress. When the Stress is less than the Critical value, the crack is subject to the force of chemical bonds during the crack propagation process, and crack arrest occurs. When the Stress is greater than the Critical value, the glass fibre will undergo destructive Fracture. In this paper, long-term tensile tests were carried out on glass fibre and a glass fibre composite under different constant tensile Stress conditions. The Fracture times of the glass fibre and glass fibre composite under different tensile Stresses were obtained, the Critical Fracture Stress of glass fibre was inferred, and the Fracture mechanism was explained.