Comparison of composite damage growth tools for static behavior of notched composite laminates

2016 ◽  
Vol 51 (10) ◽  
pp. 1493-1524 ◽  
Author(s):  
Stephen P Engelstad ◽  
Stephen B Clay
Keyword(s):  
Air Force ◽  
Composite Laminates ◽  
Fatigue Loading ◽  
Lessons Learned ◽  
Progressive Damage ◽  
Damage Analysis ◽  
Damage Growth ◽  
Composite Damage ◽  
Open Hole ◽  
Air Force Research Laboratory

This paper provides overall comparisons of the static results of an Air Force Research Laboratory exploration into the state of the art of existing technology in composite progressive damage analysis. In this study, blind and re-calibration bench-marking exercises were performed using nine different composite progressive damage analysis codes on unnotched and notched (open-hole) composite coupons under both static and fatigue loading. This paper summarizes the results of the static portion of this program. Comparisons are made herein of specimen stiffness and strength predictions against each other and the test data. Overall percent error data is presented, as well as a list of observations and lessons learned during this year-long effort.

Comparison of composite damage growth tools for fatigue behavior of notched composite laminates

2017 ◽  
Vol 51 (15) ◽  
pp. 2227-2249 ◽  
Author(s):  
SP Engelstad ◽  
SB Clay
Keyword(s):  
Composite Laminates ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Lessons Learned ◽  
Progressive Damage ◽  
Damage Analysis ◽  
Damage Growth ◽  
Composite Damage ◽  
Open Hole ◽  
Air Force Research Laboratory

This paper provides overall comparisons of the fatigue results of an Air Force Research Laboratory exploration into the state of the art of existing technology in composite progressive damage analysis. This program performed blind and recalibration benchmarking exercises for nine different composite progressive damage analysis codes using unnotched and open-hole composite coupons under both static and fatigue loading. This paper summarizes the results of the fatigue portion of this program in which seven of the codes were evaluated. Comparisons are made herein for all seven participants’ predictions with the test data. Overall percent error data are presented, as well as a long list of observations and lessons learned during this year-long effort.

Benchmarking of composite progressive damage analysis methods: The background

2016 ◽  
Vol 51 (10) ◽  
pp. 1325-1331 ◽  
Author(s):  
Stephen B Clay ◽  
Stephen P Engelstad
Keyword(s):  
Air Force ◽  
Research Laboratory ◽  
Tolerance Analysis ◽  
Progressive Damage ◽  
Damage Analysis ◽  
Damage Growth ◽  
Analysis Methods ◽  
Composite Damage ◽  
Damage Tolerance Analysis ◽  
Air Force Research Laboratory

This article introduces an Air Force Research Laboratory study, which performed static and fatigue benchmark exercises for nine composite progressive damage analysis methods. Air Force Research Laboratory is interested in exploring the feasibility of these progressive damage analysis methods to predict composite damage growth for the purposes of improved durability and damage tolerance analysis of composite aircraft structure. This article gives the background, goals, motivation, and guiding principles of the study and provides brief descriptions of the teams that participated and the tools that were utilized.

Experimental results of quasi-static testing for calibration and validation of composite progressive damage analysis methods

2016 ◽  
Vol 51 (10) ◽  
pp. 1333-1353 ◽  
Author(s):  
Stephen B Clay ◽  
Philip M Knoth
Keyword(s):  
Air Force ◽  
Research Laboratory ◽  
Experimental Results ◽  
Progressive Damage ◽  
Damage Analysis ◽  
Calibration And Validation ◽  
Computed Tomography Images ◽  
Analysis Methods ◽  
Static Conditions ◽  
Air Force Research Laboratory

The Air Force Research Laboratory directed a research program to evaluate nine different composite progressive damage analysis methods under both quasi-static and fatigue loading. This paper describes the coupon tests that were performed at the Air Force Research Laboratory for calibration and validation of the methods under quasi-static conditions. The basic elastic and failure properties of unidirectional IM7/977-3 graphite/epoxy were first determined in order to properly calibrate the models. Validation tests were then performed on unnotched and open-hole coupons with three different laminate stacking sequences under both tension and compression loading conditions. This paper summarizes these experimental results and provides X-ray computed tomography images at subcritical load levels.

Failure simulations of open-hole IM7/977-3 coupons subjected to fatigue loading using Autodesk Helius PFA

2016 ◽  
Vol 51 (15) ◽  
pp. 2119-2129 ◽  
Author(s):  
Richard W Dalgarno ◽  
Jason E Action ◽  
Donald H Robbins ◽  
Stephen P Engelstad
Keyword(s):  
Air Force ◽  
Carbon Fibers ◽  
Fatigue Loading ◽  
X Rays ◽  
Hole Configuration ◽  
Open Hole ◽  
Modeling Strategy ◽  
Improve Correlation ◽  
Damage Tolerant ◽  
Air Force Research Laboratory

Finite element simulations of three laminates in open-hole configuration subjected to constant amplitude tension–tension fatigue loading are investigated as part of the Damage Tolerant Design Principles program organized by the Air Force Research Laboratory. All coupons were made from unidirectional IM7/977-3 plies, which are composed of intermediate modulus carbon fibers and a toughened epoxy matrix. Government furnished experimental data from an assortment of fatigue loaded unnotched coupons were used to characterize the behavior of the composite material in the simulations. The commercial software Autodesk Helius PFA was used to model the non-linear response of the material. Blind simulations of coupon stiffness and damage at several cycle numbers and residual coupon tensile and compressive strengths are benchmarked against experimental measurements and X-rays. Upon review of the experimental results, a second round of simulations was performed where the modeling strategy was updated to improve correlation to experiment.

Progressive Fatigue Damage Simulation in Laminated Composites Based on Explicit Finite Element Formulation

2019 ◽  
Vol 64 (2) ◽  
pp. 1-12
Author(s):  
Yuri Nikishkov ◽  
Guillaume Seon ◽  
Andrew Makeev
Keyword(s):  
Finite Element ◽  
Laminated Composites ◽  
Test Methods ◽  
Remaining Useful Life ◽  
Image Correlation ◽  
Progressive Damage ◽  
Damage Analysis ◽  
Explicit Finite Element ◽  
Analysis Methods ◽  
Open Hole

Advanced polymeric composites are playing a major role in designing high-performance and lightweight vertical lift structures. However, uncertain residual strength and remaining useful life of the composite rotor and airframe structures due to complexity of failure mechanisms and susceptibility to manufacturing irregularities, which may be precursors to structural damage, impose risks that cannot be mitigated exclusively by time-consuming and costly experimental iterations. Validated analysis techniques accelerating design, certification, and qualification of composite structures are needed. Our team has been taking essential steps toward improving confidence in material qualification for laminated composites. The first step started with our reduced lamina test methods, short-beam shear, and small-plate twist based on digital image correlation measuring as a subset the standard material properties and, in addition, key properties that cannot be currently measured using any standard test methods. The lamina properties provide essential material input data for laminate analysis. The laminate analysis was the second step increasing confidence in material qualification. A known weakness of the existing progressive damage analysis methods is the lack of effective techniques to predict ultimate failure. The newly developed methodology relies on explicit finite element modeling and eliminates convergence issues in the ply-level progressive damage analysis methods due to severe nonlinear discontinuities after propagation of damage beyond detectable size. This work shows results of applying this methodology to nanosilica-toughened IM7/PMT-F3GHT open-hole tension strength/fatigue, open-hole compression strength/fatigue, and bearing strength multidirectional laminate configurations. The ability to predict progression of damage from initiation to ultimate strength and fatigue for advanced material systems including IM7/PMT-F3GHT carbon/epoxy reinforced by nanosilica has been demonstrated for the first time.

Fatigue Life Prediction of Composite Laminates Based on Progressive Damage Analysis

2014 ◽  
Vol 1064 ◽  
pp. 108-114 ◽  
Author(s):  
Jun Kang ◽  
Zhi Dong Guan ◽  
Zeng Shan Li ◽  
Zhun Liu
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Material Property ◽  
Composite Laminates ◽  
Life Prediction ◽  
Shear Failure ◽  
Fatigue Life Prediction ◽  
Progressive Damage ◽  
Damage Analysis ◽  
Fatigue Damage Analysis

A three dimensional analysis model is developed on the fatigue life prediction of composite laminates based on a progressive damage analysis. This model consists of stress analysis, fatigue failure analysis and material property degradation. Teserpe’s failure criteria is used to fatigue damage analysis. Fiber tensile/compressive breakage, matrix tensile/compressive cracking, matrix/fiber shear failure and tension/compression delamination are considered in fatigue damage analysis. The methodologies of sudden degradation and gradual degradation are both applied in the material property degradation. The stiffness and strength gradual degradation is based on the Shokrieh fatigue model, which is based on fatigue test for unidirectional laminates. In order to consider the scatter of the material in the practical structures, the stiffness and strength of the material are randomly distributed using normal distribution in the numerical model. The progressive fatigue damage model is developed in finite element code ABAQUS through user subroutine UMAT, which can simulate the fatigue damage process. Fatigue life of different ply stacking sequences and geometries composite laminates under different cycle loading are predicted. The predicted fatigue life is in good agreement with the experimental results.

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