Characterization of piercing damage in CFRP cross-ply laminates after punch shear machining via impact loading

2021 ◽  
pp. 002199832110316
Author(s):  
Shinya Matsuda ◽  
Kohei Mabe ◽  
Keiji Ogi ◽  
Shigeki Yashiro ◽  
Yoshifumi Kakudo
Keyword(s):  
Shear Deformation ◽  
Composite Structures ◽  
Polymer Matrix Composites ◽  
Shear Loading ◽  
Matrix Composites ◽  
Plane Shear ◽  
Reinforced Plastic ◽  
Out Of Plane ◽  
Machining Operations

In industrial processes, piercing and trimming are essential because composite structures are usually manufactured in a near-net shape to reduce machining operations. Punching and shear cutting using out-of-plane shear loading are expected to increase productivity. Nevertheless, little is known about the effects of such operations on polymer-matrix composites. This study presents on the characterization of piercing damage in typical carbon fiber reinforced plastic (CFRP) cross-ply laminates [0°2/90°2]s after punching using quasi-static (QS) and drop-weight impact (DWI) loadings. During QS punching, the upper and lower ply interfaces delaminate due to the high shear stress to cut fibers and gradual shear deformation in the middle ply; however, during DWI punching at a low impact velocity, delamination of the lower ply interface can be reduced due to the localization of shear deformation, as compared to that in QS punching. Finally, the damage accumulation process during DWI punching is discussed.

scholarly journals Analysis of Elastic Medium with Nonconcentric Two Circular Inclusions under Out-of-Plane Shear Loading.

1998 ◽  
Vol 64 (618) ◽  
pp. 438-444 ◽  
Author(s):  
Kenichi HIRASHIMA ◽  
Shigerou NAKANE ◽  
Mutsumi MIYAGAWA ◽  
Shinji KIKUCHI
Keyword(s):  
Elastic Medium ◽  
Shear Loading ◽  
Plane Shear ◽  
Out Of Plane

Study on the Stress Concentration in GFRP Composite Plates with Multiple Cut-Outs Subjected to Shear Loading

2018 ◽  
Vol 877 ◽  
pp. 446-452
Author(s):  
R.S. Aleena ◽  
R.S. Priyadarsini
Keyword(s):  
Stress Concentration ◽  
Composite Structures ◽  
Composite Plates ◽  
Shear Loading ◽  
Space Vehicles ◽  
Plane Shear ◽  
Civil Infrastructures ◽  
Glass Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Engineering Practices

The composite materials are widely used nowadays as major parts of structures in many industries like aerospace, marine, automobile, space vehicles and also for the repair and replacement of civil infrastructures. Stresses are vital parameters considered in the design of structures. Any irregularities in shape, materials, or the presence of cut-outs create localized stress concentration and reduce the capacity of the material to take loads. The anisotropic behaviour of composite structures also makes the analysis more complex. Shear loading often exists in the engineering practices such as in aerospace due to heavy aerodynamic loads. So in the present study the effects of different parameters like layup sequences, number of plies, proximity of cut-outs, shapes and arrangements of cut-outs under in-plane shear loading on the glass fibre reinforced polymer (GFRP) plate with multiple cut-outs are studied using ABAQUS. The results from the study show that all the parameters considered for the study affects the stress concentration considerably. The observations are analysed then and the final conclusions are presented.

scholarly journals Viscoelastic Characterization of Short Fibres Reinforced Thermoplastic in Tension and Shearing

2010 ◽  
Vol 24-25 ◽  
pp. 419-423 ◽  
Author(s):  
A. Andriyana ◽  
Luisa Silva ◽  
Noelle Billon
Keyword(s):  
Mechanical Response ◽  
Polymer Matrix Composites ◽  
Mechanical Analysis ◽  
Integrated Modelling ◽  
Matrix Composites ◽  
Moulding Process ◽  
Permanent Strain ◽  
Mould Filling ◽  
Injection Moulding Process

The present work can be regarded as a first step toward an integrated modelling of mould filling during injection moulding process of polymer matrix composites and the resulting material behaviour under service loading conditions. More precisely, the emphasis of the present research is laid on the development of a mechanical model which takes into account the processing-induced microstructure and is capable to predict the mechanical response of the material. In the Part I, a set of experiments which captures the mechanical behaviour of an injection moulded short fibre reinforced under different strain histories is described. Three mechanical testing are conducted: Dynamic Mechanical Analysis (DMA), uniaxial tension and simple shear. Tests show that the material exhibits complex responses mainly due to non-linearity, anisotropy, time/rate-dependence, hysteresis and permanent strain. Moreover, the relaxed state of the material is characterized by the existence of a so-called anisotropic equilibrium hysteresis independently of the prescribed strain rate.

Azimuthally Scanned Angled-Beam Pulse-Echo Ultrasound for Characterization of Impact Damage in Composites

2020 ◽  
Vol 3 (3) ◽  
Author(s):  
John T. Welter ◽  
Daniel M. Sparkman ◽  
John C. Aldrin ◽  
David Zainey ◽  
Tyler Lesthaeghe ◽  
...  
Keyword(s):  
Polymer Matrix Composites ◽  
Impact Damage ◽  
Slow Crack Growth ◽  
Normal Incidence ◽  
Matrix Composites ◽  
Transverse Cracks ◽  
X Ray Computed ◽  
Ultrasound Inspection ◽  
Pulse Echo

Abstract Characterization of barely visible impact damage (BVID) in polymer matrix composites (PMCs) is necessary to use slow crack growth damage tolerance models and evaluate remaining life of PMC components. Azimuthally scanned angled-beam pulse-echo ultrasound is investigated as a complimentary technique to normal incidence ultrasound inspection of BVID in PMCs to characterize delamination fields. It is found that there is a correlation between signals present in the azimuthally scanned angled-beam pulse-echo ultrasound C-scans and transverse cracks seen in X-ray computed tomography inspection. These transverse cracks are not readily identifiable as transverse cracks in normal incidence C-scan inspection.

Experimental and theoretical investigation of mixed mode I/III brittle fracture of U-notched polystyrene components

2017 ◽  
Vol 53 (1) ◽  
pp. 15-25 ◽  
Author(s):  
A.R. Torabi ◽  
Behnam Saboori
Keyword(s):  
Brittle Fracture ◽  
Mixed Mode ◽  
General Purpose ◽  
Shear Loading ◽  
Mode I ◽  
Mean Stress ◽  
Plane Shear ◽  
Out Of Plane ◽  
Notch Tip ◽  
Stress Criteria

Brittle fracture of components made of the general-purpose polystyrene and weakened by an edge U-notch under combined tension/out-of-plane shear loading conditions (mixed mode I/III) has not been studied yet experimentally or theoretically. In this research, a recently developed loading fixture is employed for experimentally investigating the fracture of U-notched general-purpose polystyrene samples with various notch tip radii of 0.5, 1, 2 and 4 mm when they are subjected to different combinations of tension/out-of-plane shear. The samples are fabricated with four different notch tip radii with the purpose of assessing the influence of this geometrical parameter. The experimental values of fracture load and out-of-plane fracture angle are theoretically predicted by the two stress-based criteria of point stress and mean stress lately extended to general loading case of mixed mode I/II/III. It is shown that both the point stress and mean stress criteria provide acceptable predictions to fracture behavior of U-notched general-purpose polystyrene specimens. The critical distances needed for the point stress and mean stress criteria are determined based on the experimental results of the U-notched samples tested under pure mode I loading. No meaningful difference is found between the fracture loads and fracture initiation angles predicted by the point stress and mean stress criteria. It is also observed that as the mode III contribution in the applied mixed mode I/III loading increases, a larger total external load is needed for the fracture of U-notched general-purpose polystyrene specimens to occur.

Sign in / Sign up

Export Citation Format

Share Document