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Comparing the effect of geometry and stiffness on the effective load paths in non-symmetric laminates

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Standard

Comparing the effect of geometry and stiffness on the effective load paths in non-symmetric laminates. / Minera Rebulla, Sergio; Patni, Mayank; Weaver, Paul; Pirrera, Alberto; O'Donnell, Matt.

AIAA SCITECH 2019, San Diego California, 7-11 January. American Institute of Aeronautics and Astronautics Inc. (AIAA), 2019. AIAA 2019-1766.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Harvard

Minera Rebulla, S, Patni, M, Weaver, P, Pirrera, A & O'Donnell, M 2019, Comparing the effect of geometry and stiffness on the effective load paths in non-symmetric laminates. in AIAA SCITECH 2019, San Diego California, 7-11 January., AIAA 2019-1766, American Institute of Aeronautics and Astronautics Inc. (AIAA). https://doi.org/10.2514/6.2019-1766

APA

Minera Rebulla, S., Patni, M., Weaver, P., Pirrera, A., & O'Donnell, M. (2019). Comparing the effect of geometry and stiffness on the effective load paths in non-symmetric laminates. In AIAA SCITECH 2019, San Diego California, 7-11 January [AIAA 2019-1766] American Institute of Aeronautics and Astronautics Inc. (AIAA). https://doi.org/10.2514/6.2019-1766

Vancouver

Minera Rebulla S, Patni M, Weaver P, Pirrera A, O'Donnell M. Comparing the effect of geometry and stiffness on the effective load paths in non-symmetric laminates. In AIAA SCITECH 2019, San Diego California, 7-11 January. American Institute of Aeronautics and Astronautics Inc. (AIAA). 2019. AIAA 2019-1766 https://doi.org/10.2514/6.2019-1766

Author

Minera Rebulla, Sergio ; Patni, Mayank ; Weaver, Paul ; Pirrera, Alberto ; O'Donnell, Matt. / Comparing the effect of geometry and stiffness on the effective load paths in non-symmetric laminates. AIAA SCITECH 2019, San Diego California, 7-11 January. American Institute of Aeronautics and Astronautics Inc. (AIAA), 2019.

Bibtex

@inproceedings{e49a226e439c4be1ae1f75c5ce88bb3a,
title = "Comparing the effect of geometry and stiffness on the effective load paths in non-symmetric laminates",
abstract = "In aerospace composite material design, it is common to encounter load bearing components that vary in thickness across their length. In plate design, ply drops, tow-steering, and the addition of stiffeners, all act to change both the section geometry and the effective stiffness of the part. Often, due to aerodynamic design constraints, the geometric profile must transition non-symmetrically, i.e. thickness is built up from a reference surface, meaning the mid-surface of the plate does not remain on a constant plane. These localised changes in geometry, and associated change of position of the mid-surface, lead to inherently three-dimensional states of stress. As a consequence, and especially for composite structures, there is the potential for significant through-thickness stresses and/or stress concentrations, leading to failure—for example debonding or delamination. By investigating the effects of geometric and effectivestiffness changes, we are able to gain physical insight into structural behaviour in the regionsof geometric transition. This is achieved through a parametric study, whereby we compare thebehaviour as predicted by Classical Laminate Theory—a commonly utilised two-dimensionalapproach—with a finite element analysis based on the Unified Formulation by Carrera andco-workers. Based on these investigations, we are able to illustrate how rates of profile changeand/or stiffness variation are linked to variance in the predicted location of the neutral plane ofthe two approaches which acts as a proxy measure for predicting through-thickness behaviour.Finally, we discuss the potential opportunity to utilise laminates that possess non-standardlayups to tailor the load path through geometric transitions, thus offering a potential route forelastic tailoring that minimises undesirable through-thickness stresses.",
author = "{Minera Rebulla}, Sergio and Mayank Patni and Paul Weaver and Alberto Pirrera and Matt O'Donnell",
year = "2019",
month = "1",
day = "7",
doi = "10.2514/6.2019-1766",
language = "English",
isbn = "9781624105784",
booktitle = "AIAA SCITECH 2019, San Diego California, 7-11 January",
publisher = "American Institute of Aeronautics and Astronautics Inc. (AIAA)",
address = "United States",

}

RIS - suitable for import to EndNote

TY - GEN

T1 - Comparing the effect of geometry and stiffness on the effective load paths in non-symmetric laminates

AU - Minera Rebulla, Sergio

AU - Patni, Mayank

AU - Weaver, Paul

AU - Pirrera, Alberto

AU - O'Donnell, Matt

PY - 2019/1/7

Y1 - 2019/1/7

N2 - In aerospace composite material design, it is common to encounter load bearing components that vary in thickness across their length. In plate design, ply drops, tow-steering, and the addition of stiffeners, all act to change both the section geometry and the effective stiffness of the part. Often, due to aerodynamic design constraints, the geometric profile must transition non-symmetrically, i.e. thickness is built up from a reference surface, meaning the mid-surface of the plate does not remain on a constant plane. These localised changes in geometry, and associated change of position of the mid-surface, lead to inherently three-dimensional states of stress. As a consequence, and especially for composite structures, there is the potential for significant through-thickness stresses and/or stress concentrations, leading to failure—for example debonding or delamination. By investigating the effects of geometric and effectivestiffness changes, we are able to gain physical insight into structural behaviour in the regionsof geometric transition. This is achieved through a parametric study, whereby we compare thebehaviour as predicted by Classical Laminate Theory—a commonly utilised two-dimensionalapproach—with a finite element analysis based on the Unified Formulation by Carrera andco-workers. Based on these investigations, we are able to illustrate how rates of profile changeand/or stiffness variation are linked to variance in the predicted location of the neutral plane ofthe two approaches which acts as a proxy measure for predicting through-thickness behaviour.Finally, we discuss the potential opportunity to utilise laminates that possess non-standardlayups to tailor the load path through geometric transitions, thus offering a potential route forelastic tailoring that minimises undesirable through-thickness stresses.

AB - In aerospace composite material design, it is common to encounter load bearing components that vary in thickness across their length. In plate design, ply drops, tow-steering, and the addition of stiffeners, all act to change both the section geometry and the effective stiffness of the part. Often, due to aerodynamic design constraints, the geometric profile must transition non-symmetrically, i.e. thickness is built up from a reference surface, meaning the mid-surface of the plate does not remain on a constant plane. These localised changes in geometry, and associated change of position of the mid-surface, lead to inherently three-dimensional states of stress. As a consequence, and especially for composite structures, there is the potential for significant through-thickness stresses and/or stress concentrations, leading to failure—for example debonding or delamination. By investigating the effects of geometric and effectivestiffness changes, we are able to gain physical insight into structural behaviour in the regionsof geometric transition. This is achieved through a parametric study, whereby we compare thebehaviour as predicted by Classical Laminate Theory—a commonly utilised two-dimensionalapproach—with a finite element analysis based on the Unified Formulation by Carrera andco-workers. Based on these investigations, we are able to illustrate how rates of profile changeand/or stiffness variation are linked to variance in the predicted location of the neutral plane ofthe two approaches which acts as a proxy measure for predicting through-thickness behaviour.Finally, we discuss the potential opportunity to utilise laminates that possess non-standardlayups to tailor the load path through geometric transitions, thus offering a potential route forelastic tailoring that minimises undesirable through-thickness stresses.

U2 - 10.2514/6.2019-1766

DO - 10.2514/6.2019-1766

M3 - Conference contribution

SN - 9781624105784

BT - AIAA SCITECH 2019, San Diego California, 7-11 January

PB - American Institute of Aeronautics and Astronautics Inc. (AIAA)

ER -