Experimental stress determination of blunt notches under combinations of modes I and II loading

Eipakchi, Hamidreza; Ayatollahi, M.R.; Daneshfar, M.; Bahrami, Bahador

doi:10.1016/j.engstruct.2022.115517

Cited by 1 publication

(1 citation statement)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This approach is nowadays extensively applied to obtain displacement and strain fields from images of a loaded part. It is applicable not only for metals, but also for polymers such as polymethyl methacrylate (PMMA) 33,34 as well as for fiber reinforced polymers e.g., Basalt fiber reinforced polypropylene and glass fiber reinforced polypropylene. 11,19 To perform DIC in this work, a speckle pattern (gray scale) is applied to the surface of the object (a white layer is first applied and then sprayed with random black dots).…”

Section: Materials and Experimental Testingmentioning

confidence: 99%

Thermo-visco mechanical behavior of glass fiber reinforced thermoplastic composite

Faddoul,

Rahme,

Guines

et al. 2023

Journal of Composite Materials

View full text Add to dashboard Cite

Thermoplastic composite materials are being increasingly used in many domains, such as automotive, marine and aeronautics. This growing interest is due to the relatively good mechanical properties and the recycle-ability of these materials. In various heat assisted forming technologies, thermoplastic composites may be subjected to severe conditions such as high temperatures, complex strain paths and potentially significant strain rates. This is expected to highly influence the overall behavior of these materials and make the characterization of their mechanical behavior more complicated. In this paper, the mechanical behavior of discontinuous glass fiber reinforced polypropylene composite is investigated at temperatures going from room temperature (RT) to 120°C and strain rates ranging from quasi-static conditions to 10 s−1 by means of uniaxial tensile tests. The effect of material orientation is also investigated at RT and quasi-static strain rate of 0.001 s−1 pointing out a clear anisotropic behavior. The tensile properties including Young’s modulus E, ultimate tensile strength σ ult and strain at failure ɛ f are determined based on the Standard ISO-527 reporting an obvious sensitivity of the material to temperature and strain rate. Based on literature review, the phenomenological isotropic constitutive model of G’Sell and Jonas, originally designed for unreinforced semi-crystalline polymers, is selected to describe the mechanical behavior of the studied material. A modification of the original constitutive equation is proposed for a better representation of the overall behavior of the material at different temperature and strain rate conditions. Finally, the validity of this phenomenological law calibrated by means of the uniaxial tests, is evaluated for an equi-biaxial loading state close to that encountered by the material during heat assisted sheet forming process. The significant disagreement highlighted between numerical and experimental results proved that the uniaxial tensile tests are not sufficient to characterize the behavior of the material when a complex loading condition is imposed.

show abstract