Polymer Matrix Woven Fabric Composites Subjected to Low Velocity Impact: Part I-Damage Initiation Studies

Abstract

An investigation was undertaken to study the damage initiation behavior in polymer matrix laminated composite plates subjected to a transverse central low velocity point impact load. Inplane failure of the layers in the form of matrix cracking/lamina splitting and delaminations were the primary objectives of the study. The study has been carried out using modified Hertz contact law and an inhouse three-dimensional transient finite element analysis (FEA) code. The inplane failure functions and the interlaminar failure functions have been predicted using quadratic failure criteria. The inhouse FEA code was validated with other analytical studies and the experimental results in our earlier work. The present studies have been carried out on different plain weave fabric laminated composite plates, simply supported on all four sides. For comparison, impact behavior of balanced symmetric crossply (CP) laminates made of unidirectional (UD) layers and UD composites has been included. The studies have been carried out with plate dimensions of 150 mm x 150 mm with different plate thicknesses. Incident impact velocity in the range of 1 m/sec to 3 m/sec and impactor mass of 50 gm are considered. General observations on the distribution of failure functions and the initiation of damage are presented.

Polymer Matrix Woven Fabric Composites Subjected to Low Velocity Impact: Part III—Effect of Incident Impact Velocity and Impactor Mass

“…Material of the plate and the impactor was steel. The results obtained for contact force history and displacement history for the plate and the impactor by the present inhouse FEA code and that obtained by Karas were compared, and a very good correlation was obtained [12,13,17,18].…”

“…For this, an interlaminar failure function based on through-the-thickness quadratic failure criterion as proposed by Brewer-Lagace has been used [18,21]. An interlaminar failure function, I is defined as follows: Here, σ 3 , τ 23 and τ 31 are the induced stress components and Z, S 23 and S 31 are the corresponding strength values.…”

Experimental impact study on unidirectional glass-carbon hybrid composite laminates

“…They found improvements in the load carrying capability of hybrid composites as compared with carbon/epoxy laminates with slight reduction in stiffness and enhancement in damage tolerance of structures by hybridization. Naik et al [8,9] have published various works on the impact of polymer matrix woven fiber composites, reporting that the maximum displacement and duration of impact decreases with increase in in-plane modulus of elasticity. They also reported that the delamination mode is the first possible mode of failure, and that failure is often initiated at the top interface [7] .…”

Durability and failure mechanics of woven carbon composites under repeated impact loading in Arctic conditions

“…Most of the previous impact studies have focused on single low-velocity and repeated impact at room temperature. Naik et al (2000) investigated the damage imparted to woven-fabric and cross-ply E-glass/epoxy and carbon/epoxy laminates under low-velocity (1 and 3 m/s) impact. They reported that woven-fabric laminates were more resistant to in-plane impact damage than cross-ply lamiates.…”