Correlations between Damage Accumulation and Strength Degradation of Fiber Reinforced Composites Subjected to Cyclic Loading

D’Amore, Alberto; Grassia, Luigi; Ceparano, Angelo

doi:10.1016/j.proeng.2016.11.674

Cited by 9 publications

(7 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They disclose greater degradation of material properties under fatigue load than the residual strength model and the change of elastic properties can be easily measured using non-destructive techniques [55,56]. The fatigue residual strength/stiffness models recently proposed in the literature [12,18,36,37,44,46,47,54,57,58,59,60,61,62] take into account different loading parameters. Some of the fatigue models are proposed for constant amplitude loadings or include only selected loading parameters.…”

Section: Fatigue Life Modelmentioning

confidence: 99%

“…The expected fatigue lives for performed step-wise fatigue tests using the proposed technique are given in Table 2. It should be noted that fatigue of composites is a stochastic phenomenon and depends on the sequence of different damage accumulation mechanisms occurring at different length scales and the statistical distribution of defects [62]. The fatigue life of composite structures can vary even some two orders of magnitude [73].…”

Section: Fatigue Model Calibrationmentioning

confidence: 99%

“…The expected numbers of cycles to failure Nfprog, which are given in the Table 2, are evaluated using fatigue tests subjected to different loading conditions. In contrast to the statistical approach reported in papers [62,64,67,73,74,75], the expected fatigue life Nfprog evaluated in the paper using single step-wise fatigue tests have a deterministic nature. It is obvious that for practical application, it is necessary to take into account statistical nature of fatigue phenomenon, loading history, environmental conditions, etc.…”

Section: Fatigue Model Calibrationmentioning

confidence: 99%

See 2 more Smart Citations

Estimation of Notched Composite Plates Fatigue Life Using Residual Strength Model Calibrated by Step-Wise Tests

Romanowicz

Muc

2018

Materials

View full text Add to dashboard Cite

The proposed new technique of fatigue life prediction for notched composite plates is based on a residual strength model calibrated with the use of step-wise fatigue tests. It was proposed to calibrate the fatigue model with fatigue tests in which load conditions are in a step-wise fashion. The adopted fatigue model takes into account the most important loading parameters such as testing frequency, stress ratio, layer orientation and maximal fatigue stress. It was demonstrated that with the use of step-wise fatigue tests, it is possible to calibrate the fatigue model for a particular material and structure with the use of fewer samples. In the experimental tensile and fatigue tests TVR 380 M12/26%/R-glass/epoxy composite plates [+45°/−45°]4 with circular and elliptical cut-outs were used. The fatigue tests were performed under different loading conditions. The influence of testing frequency, stress ratio, maximal fatigue load and also geometry of the cut-out on damage growth rate and fatigue life were studied. The predicted fatigue life was in good agreement with the durability determined experimentally in all investigated samples.

show abstract

Section: Fatigue Life Modelmentioning

confidence: 99%

Section: Fatigue Model Calibrationmentioning

confidence: 99%

Section: Fatigue Model Calibrationmentioning

confidence: 99%

See 1 more Smart Citation

Estimation of Notched Composite Plates Fatigue Life Using Residual Strength Model Calibrated by Step-Wise Tests

Romanowicz

Muc

2018

Materials

View full text Add to dashboard Cite

show abstract

“…Up to date, for the generality and complexity of the fatigue-damage models for the unidirectional FRP materials subjected to multiaxial loading [19][20][21][22], most current studies on the optimization of the anchoring system were conducted based on stress analysis and cannot assess or predict the degree of damage to CFRP rods in the anchoring section under specific fatigue loading. Consequently, experimental studies remain an indispensable means to evaluate the performance of the anchoring system.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of Fatigue Capacity of Bending-Anchored CFRP Cables

Zhu²,

2023

Polymers

View full text Add to dashboard Cite

In this study, the variation of fatigue stiffness, fatigue life, and residual strength, as well as the macroscopic damage initiation, expansion, and fracture of CFRP (carbon fiber reinforced polymer) rods in bending-anchored CFRP cable, were investigated experimentally to verify the anchoring performance of the bending anchoring system and evaluate the additional shear effect caused by bending anchoring. Additionally, the acoustic emission technique was used to monitor the progression of critical microscopic damage to CFRP rods in a bending anchoring system, which is closely related to the compression-shear fracture of CFRP rods within the anchor. The experimental results indicate that after the fatigue cycles of two million, the residual strength retention rate of CFRP rod was as high as 95.1% and 76.7% under the stress amplitudes of 500 MPa and 600 MPa, indicating good fatigue resistance. Moreover, the bending-anchored CFRP cable could withstand 2 million cycles of fatigue loading with a maximum stress of 0.4 σult and an amplitude of 500 MPa without obvious fatigue damage. Moreover, under more severe fatigue-loading conditions, it can be found that fiber splitting in CFRP rods in the free section of cable and compression-shear fracture of CFRP rods are the predominant macroscopic damage modes, and the spatial distribution of macroscopic fatigue damage of CFRP rods reveals that the additional shear effect has become the determining factor in the fatigue resistance of the cable. This study demonstrates the good fatigue-bearing capacity of CFRP cable with a bending anchoring system, and the findings can be used for the optimization of the bending anchoring system to further enhance its fatigue resistance, which further promotes the application and development of CFRP cable and bending anchoring system in bridge structures.

show abstract

“…The three stages of damage accumulation can be distinguished for a wide variety of composite materials. However, while the extent of the individual stages causing substantial properties' degradation can strongly depend on the layup and fiber's geometry (including short and random continuous fibers), it is observed that the CDS develops in the first cycles decades of fatigue life, namely from 1 to 10 3 cycles, whatever the category of composite in play [8][9][10][11][12][13][14]. The above observations draw to the conclusion that the overall fatigue behavior depends on the behavior of the matrix in situ resulting from the constraint exerted by the reinforcement, which results in complex stress fields under load.…”

Section: Introductionmentioning

confidence: 99%

The Anomalies of Polymers at Nanoscale as a Tool to Enhance the Fatigue Life of Structural Composites

D’Amore

Grassia

2019

MSF

Self Cite

View full text Add to dashboard Cite

The “in service “properties' of high performance composites degrade due to the development of different damage modes occurring hierarchically at different length and time (cycles) scales, from diffuse crackand crazing within the polymer matrix, to fiber-matrix interface failure, to ply rupture and delamination where catastrophic failure occurs. The density of cracks within the matrix saturates at very early stage of the service life of the composite component and this “Critical Damage State” (CDS) triggers the other damage modes. Thus, shifting the CDS toward higher number of cycles allows enhancing the overall fatigue performances of composites, that is the main objective of our proposal. The matrix weakness is due to the residual stresses (of order of magnitude of the matrix strength) that accumulate as consequence of the manufacturing process. In order to relax the residual stresses we propose to take advantage of the anomalies of nanoconfined thermoplastic polymers that show a negative coefficient ofthermal expansion at temperatures below Tg. Silica microspheres can be covered by polymer shells of 10-40 nanometers and added to the reactive resin in order to counter balance the resin contraction through the expansion of the nanoconfined polymer, during cooling.

show abstract

Correlations between Damage Accumulation and Strength Degradation of Fiber Reinforced Composites Subjected to Cyclic Loading

Cited by 9 publications

References 6 publications

Estimation of Notched Composite Plates Fatigue Life Using Residual Strength Model Calibrated by Step-Wise Tests

Estimation of Notched Composite Plates Fatigue Life Using Residual Strength Model Calibrated by Step-Wise Tests

Experimental Investigation of Fatigue Capacity of Bending-Anchored CFRP Cables

The Anomalies of Polymers at Nanoscale as a Tool to Enhance the Fatigue Life of Structural Composites

Contact Info

Product

Resources

About