Notch effect on strength and fatigue life of woven composite laminates

Abstract

This paper presents an experimental and numerical study of the notch effect on strength and fatigue life of double edge notched (DEN) composite laminates made of woven glass fibre lamina 3238A/EW250F and woven carbon fibre lamina 3238A/CF3052. Experimental results show that the notch effect is dependent on fibre type, notch depth, load type and load sequence. A s n R d r − − − − residual strength model was proposed to account for the effects of the notch and the stress ratio, and a progressive damage algorithm was developed to predict damage propagation and residual life of composites under spectrum fatigue load. Good agreement between the experimental results and the numerical predictions has been achieved.

Finite element modeling and fatigue life prediction of helicopter composite tail structure under multipoint coordinated loading spectrum

“…The progressive damage analysis has been proven to be an effective method in predicting the fatigue life and failure process of composite structure [27] . Fig.…”

“…The metal and composite honeycomb sandwich structures are considered as the effective load transfer structures without damage due to their high mechanical performance. The strength degradation models developed in literature [27] is implemented as the material property degradation metric. Eq.…”

Comparative fatigue properties estimation of composite structural nodes

“…It is not easy to find in the literature the reports concerning comprehensive fatigue tests of a real NCFI applied in a particular airplane-structure which can be used for comparison, but phenomenon of the large difference between the ratio of static strength and the ratio of fatigue life is well described for simple composite samples having structural discontinuities. As a reference for the results presented above the investigations into notch effect on strength and fatigue life of composites can be used (Wan et al, 2019). Those investigations were carried out on rectangular GFRP and CFRP specimens (made from Figure 14 PW5 LS in the original form and in the form of transfer array woven composite laminates -unnotched or notched symmetrically in the middle) which were subjected to cyclic longitudinal loads (compression/tension with R = 10 or R = 0.05).…”

“…One can find in the literature numerous examples of investigations regarding fatigue tests performed on coupons of different FRPs, especially those whose structure is affected by notches, holes or local impact destruction (Wan et al, 2019;Kassapoglou, 2016;Wallin and Saarela, 2008;Paipetis and Katerelos, 2010;Rodzewicz, 2009). Unlike in the classic thin-wall metal structuresthe key problem regarding highly loaded light FRPs is a problem of introduction of concentrated force into thin shells.…”

Tension-Compression Fatigue Induced Stress Concentrations in Woven Composite Laminate

“…Typically, the residual strength of the laminates is experimentally measured, while analytical, empirical, and numerical models are developed for fatigue life prediction [11]. Furthermore, stress concentrations in notched composite specimens were also reported due to the T-T fatigue loading [12]. Investigating the fatigue behaviour under T-T loading is relatively simple due to the uncomplicated nature of the loading mechanism.…”