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.

GFRP Reinforcement Behaviour under Multi-Axial Stress - Experimental Study

2020 ◽  
Vol 309 ◽  
pp. 80-86
Author(s):  
Vojtech Kostiha ◽  
Frantisek Girgle ◽  
Ondřej Janus ◽  
Ivana Švaříčková ◽  
Petr Štěpánek
Keyword(s):  
Axial Stress ◽  
Shear Loading ◽  
Modern Material ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Technical Report ◽  
Fibre Reinforced Polymer ◽  
Frp Reinforcement ◽  
Glass Fibre Reinforced ◽  
Gfrp Reinforcement

This paper is focused on the design of concrete structures reinforced with modern composite material – Fibre Reinforced Polymer (FRP) reinforcement. It presents actual results from the testing of FRP rods under a simultaneous tensile and shear loading. The results were experimentally obtained on specimens of Glass Fibre Reinforced Polymer (GFRP) reinforcement. The text also points out that the widely used fib Bulletin no. 40 technical report does not provide sufficiently reliable formulas and may overestimate the load-bearing capacity of the element. Therefore, the conclusions formulated are primarily concerned with their practical use in the design of this modern material.

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.

Characteristics of In-Plane Waves in Composite Plates

2019 ◽  
Vol 24 (3) ◽  
pp. 458-466
Author(s):  
K. Renji ◽  
S. Josephine Kelvina Florence ◽  
Sameer Deshpande
Keyword(s):  
Composite Structures ◽  
Plane Waves ◽  
Phase Speed ◽  
Composite Plates ◽  
Laminated Plates ◽  
Composite Panel ◽  
Plane Shear ◽  
Aerospace Applications ◽  
Bending Waves ◽  
Isotropic Plates

The high frequency dynamic excitations generate both in-plane as well as bending waves in structures. In aerospace applications, many of these structures are made of composite materials. There are two types of in-plane motions, longitudinal and in-plane shear. Although these motions are uncoupled in isotropic materials, composite structures show coupled behaviour. The works reported on in-plane waves in composite structures assume that two in-plane motions are uncoupled as in isotropic plates. In this work, characteristics of the in-plane waves in composite laminated plates are investigated. Expressions for wavenumber, phase speed and group speed are derived. It is seen that in composite plates the two in-plane waves are coupled in longitudinal and shear propagations and are non-dispersive. The phase speeds of in-plane waves in composite plates can be much different from those determined using the expressions for isotropic plates where the waves are uncoupled. To validate the expressions derived the phase speeds of in-plane waves in a typical composite panel are determined experimentally. It is seen that the experimentally obtained phase speeds match well with the theoretical results.

scholarly journals The fracture mechanism of softwood via hierarchical modelling analysis

2019 ◽  
Vol 65 (1) ◽  
Author(s):  
Dong Wang ◽  
Lanying Lin ◽  
Feng Fu ◽  
Mizi Fan
Keyword(s):  
Stress Concentration ◽  
Wood Cell Wall ◽  
Shear Loading ◽  
Interface Debonding ◽  
Neutral Layer ◽  
Plane Shear ◽  
Hierarchical Modelling ◽  
Modelling Analysis ◽  
Initial Fracture ◽  
Shear Coupling

Abstract A hierarchical model of softwood was developed to effectively analyze stress concentration and predict initial fracture of the wood cell wall under different loading scenarios. The results indicated that the simulated stress concentration regions of the tracheid wall approximately matched the experimental initial fracture locations. The stress concentration and initial fracture of the tracheid wall under longitudinal tensile stress occurred in the S2 layer. In the cases of pure longitudinal–radial (LR) or longitudinal–tangential (LT) in-plane shear loading, the highest stresses are observed in the S1/S2 interface and the S3 layer, but the initial fractures of the tracheids of the neutral layer under the LR or LT shear stress only occurred in the S1/S2 interface. Furthermore, the tracheids of the tensile parts outermost of bending specimen were subjected to the longitudinal tension and shear coupling stresses that led to the two kinds of cracks occurring, including trumpet-shaped cracks in the S2 layer, and S1/S2 interface debonding.

Stress Concentration Near Stiff Cylindrical Inclusions under Anti-Plane Shear Loading

2020 ◽  
Vol 65 (11) ◽  
pp. 390-395
Author(s):  
E. V. Lomakin ◽  
S. A. Lurie ◽  
L. N. Rabinskiy ◽  
Y. O. Solyaev
Keyword(s):  
Stress Concentration ◽  
Shear Loading ◽  
Plane Shear ◽  
Cylindrical Inclusions

Optimum design of perforated symmetric laminates using evolutionary algorithm

2018 ◽  
Vol 53 (23) ◽  
pp. 3281-3305
Author(s):  
A Khechai ◽  
PM Mohite
Keyword(s):  
Genetic Algorithm ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Analytical Solution ◽  
Stress Concentration Factor ◽  
Failure Load ◽  
Composite Plates ◽  
Shear Loading ◽  
Effective Parameters ◽  
Circular Cutout

Here, analytical studies have been carried out to determine the optimal values of effective parameters on the stress concentration factor around a cutout using genetic algorithm. Optimum designs of single lamina as well as symmetric laminates with 4, 8 and 12 layers of graphite/epoxy and glass/epoxy plates containing a circular cutout with various sizes are presented. The work focuses on extending the analytical solution given by Greszczuk to determine the stress distribution in multilayered composite plates subjected to arbitrary in-plane loadings. This is achieved by introducing an arbitrary oriented uniaxial, biaxial and shear loading conditions into Greszczuk solution. In order to mimic as much as possible the real structural behavior, the finite-width correction factor given by Tan is used. Effective parameters on stress distribution around the circular cutout in composite plates considered as design variables include: load angle, fiber orientation, cutout size and stacking sequence of the laminate. The objective function in this study is the minimization of maximum stress concentration around the cutout which is calculated by the present analytical solution. The first ply failure load predicted using Tsai–Wu criterion is maximized for both single lamina and symmetric laminates. Also, the weight of the plates is minimized by increasing the hole size to width ratio. The results obtained by the present analytical solution compare favorably with those obtained using complex variable method. For laminated plate subjected to shear loading, the stress concentration factor decreased drastically by 48.79% compared to a single lamina. The failure load is also increased in most of the loading cases. The results also showed that the genetic algorithm code converges rapidly in most of the cases. The accuracy, quickness, low computational cost and the simplicity of the present solution encourage the designers to use it in practical applications.

Sign in / Sign up

Export Citation Format

Share Document