Experimental and numerical study of the effect of caul-sheets on corner thinning of composite laminates

Fernlund, G.; Griffith, John; Courdji, R.; Poursartip, Anoush

doi:10.1016/s1359-835x(01)00114-2

Cited by 43 publications

(20 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where E is the instantaneous elastic modulus, α is the DOC and T is the temperature. Although polymer composites are viscoelastic and their properties are time-dependent, for the cases where the modulus during cure is constantly increasing, accurate results can be obtained using this model [18,20]. For example, the CHILE approach can accurately predict residual stresses and deformation during a simple one-hold cure cycle.…”

Section: Residual Stress Formation and Representationmentioning

confidence: 99%

Multiscale characterization and representation of composite materials during processing

Zobeiry

Forghani

et al. 2016

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

Given the importance of residual stresses and dimensional changes in composites manufacturing, process simulation has been the focus of many studies in recent years. Consequently, various constitutive models and simulation approaches have been developed and implemented for composites process simulation. In this paper, various constitutive models, ranging from elastic to nonlinear viscoelastic; and simulation approaches ranging from separated flow/solid phases to multiscale integrated phases are presented and their applicability for process simulation is discussed. Attention has been paid to practical aspects of the problem where the complexity of the model coupled with the complexity and size scaling of the structure increases the characterization and simulation costs. Two specific approaches and their application are presented in detail: the pseudo-viscoelastic cure hardening instantaneously linear elastic (CHILE) and linear viscoelastic (VE). It is shown that CHILE can predict the residual stress formation in simple cure cycles such as the one-hold cycle for HEXCEL AS4/8552 where the material does not devitrify during processing. It is also shown that using this simple approach, the cure cycle can be modified to lower the residual stress level and therefore increase the mechanical performance of the composite laminate. For a more complex cure cycle where the material is devitrified during a post-cure, it is shown that a more complex model such as VE is required. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'.

show abstract

Section: Residual Stress Formation and Representationmentioning

confidence: 99%

Multiscale characterization and representation of composite materials during processing

Zobeiry

Forghani

et al. 2016

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

show abstract

“…• Pseudo-viscoelastic model: the cure hardening instantaneously linear elastic models (CHILE) have been used by some researchers for process simulation (e.g., Bogetti & Gillespie, 1992;Fernlund, Abdel-Rahman, et al, 2002;Fernlund, Griffith, Courdji, & Poursartip, 2002;Fernlund et al, 2003;Johnston et al, 2001;Lange, Toll, & Manson, 1995). In these models, the modulus changes as a function of degree of cure and temperature:…”

Section: Analytical and Numerical Approachesmentioning

confidence: 99%

“…Although these models do not capture the full complexity of viscoelastic materials, in general, it has been shown that the CHILE approach provides good predictions for curing of thermoset resins (Fernlund, Griffith, et al, 2002;Fernlund et al, 2003;Zobeiry, 2006). Although these models do not capture the full complexity of viscoelastic materials, in general, it has been shown that the CHILE approach provides good predictions for curing of thermoset resins (Fernlund, Griffith, et al, 2002;Fernlund et al, 2003;Zobeiry, 2006).…”

Section: Analytical and Numerical Approachesmentioning

confidence: 99%

The origins of residual stress and its evaluation in composite materials

Zobeiry

Poursartip

2015

Structural Integrity and Durability of Advanced Composites

Self Cite

View full text Add to dashboard Cite

“…White and Hahn (1992) and Johnston et al (2001)). In general, the CHILE constitutive model for thermoset polymers has been shown to provide good predictions in analyzing the behavior of composite materials [Fernlund et al, 2002a[Fernlund et al, , 2002b[Fernlund et al, , 2003]. However, it is known that polymers in general show viscoelastic behavior (e.g.…”

Section: Compro Materials Characterization and Effect Of Cure Cycle Onmentioning

confidence: 99%

Integrated Computational Materials Engineering for Airframe Composite Structure Applications

Engelstad

Koon

Action

et al. 2015

56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

View full text Add to dashboard Cite

IntroductionIntegrated Computational Materials Engineering (ICME) is a game-changing AFRL and industry vision to reduce the material and process development cycle time and cost, simultaneously bringing optimized material systems to the war fighter tailored to the needs of both the airframe and propulsion systems [Ref: National Materials Advisory Board]. The nearterm path to achieving these goals is through integration of material modeling capabilities. AFRL is currently working on two Foundational Engineering Problems (FEPs), one for metallic aircraft applications, and one for composites. GE Aviation and Lockheed Martin Aeronautics (LM Aero) have teamed to work the composites FEP, called "Integrated Computational Methods for Composite Materials (ICM2)" specifically targeting integration of composites processing, micromechanics, and damage progression modeling codes to address composite material development and application issues. GE is focused on engine applications, whereas LM Aero is focused on airframe applications.For the airframe specific ICM2 FEP, LM Aero is targeting the fundamental issues that drive the design of acreage composite materials on the next generation airframes. In order to meet composite airframe future needs, large scale airframe manufacturing will target larger, unitized composite assemblies with increased use of bonding and reduced part-count. Process automation will be utilized to reduce costs through reductions in touch labor. Improvements in composite design allowables are critical to optimal airframe weight (and hence performance) and must be obtained through use of higher performance resins and fibers along with reduced variability in key sizing properties. The ICM2 program intends to integrate composite process and design modeling codes to streamline the development cycle time and reduce the cost to implement such new high performance materials on next generation aircraft. For the ICM2 program's demonstration purposes LM Aero is studying the IM7/M65 bismaleimide (BMI) system for application to large acreage wing skin and web applications. M65 is an established BMI system (MRL ≥5) well suited to manufacturing using high speed automated fiber placement (AFP).BMI systems have experienced increased usage on fighter aircraft due primarily to key structural design properties such as open hole compression (OHC) and compression-strengthafter-impact (CSAI), the values for which exceed epoxies at max service temperature and moisture conditions [Rousseau et al.] These key properties often "size" the acreage of the aircraft composite skins. Bolted joint strength and acreage repair criteria are most closely related

show abstract

Experimental and numerical study of the effect of caul-sheets on corner thinning of composite laminates

Cited by 43 publications

References 8 publications

Multiscale characterization and representation of composite materials during processing

Multiscale characterization and representation of composite materials during processing

The origins of residual stress and its evaluation in composite materials

Integrated Computational Materials Engineering for Airframe Composite Structure Applications

Contact Info

Product

Resources

About