Design, Manufacture and Test of an In-Situ Consolidated Thermoplastic Variable-Stiffness Wingbox

Oliveri, Vincenzo; Zucco, Giovanni; Peeters, Daniël; Clancy, Gearóid J.; Telford, Robert; Rouhi, Mohammad; McHale, Ciarán; O’Higgins, Ronan M.; Young, Trevor; Weaver, Paul M.

doi:10.2514/1.j057758

Cited by 38 publications

(34 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This wingbox was successfully tested, loading it with a shear force and bending moment, representative of the load at 85% semi-span of a B-737/A320 sized aircraft. This work has previously been reported by Oliveri et al (11) Currently, we build upon this previous work (11) by testing the wingbox under another load case in which torsion is also introduced, i.e. a combined shear-bending-torsion (SBT) load.…”

Section: Introductionmentioning

confidence: 84%

See 1 more Smart Citation

Static test of a variable stiffness thermoplastic composite wingbox under shear, bending and torsion

et al. 2020

View full text Add to dashboard Cite

Automated manufacturing of thermoplastic composites has found increased interest in aerospace applications over the past three decades because of its great potential in low-cost, high rate, repeatable production of high performance composite structures. Experimental validation is a key element in the development of structures made using this emerging technology. In this work, a $750\times640\times240$ mm variable-stiffness unitised integrated-stiffener out-of-autoclave thermoplastic composite wingbox is tested for a combined shear-bending-torsion induced buckling load. The wingbox is manufactured by in-situ consolidation using a laser-assisted automated tape placement technique. It is made and tested as a demonstrator section located at 85% of the wing semi-span of a B-737/A320 sized aircraft. A bespoke in-house test rig and two aluminium dummy wingboxes are also designed and manufactured for testing the wingbox assembly which spans more than 3m. Prior to testing, the wingbox assembly and the test rig were analysed using a high fidelity finite element method to minimise the failure risk due to the applied load case. The experimental test results of the wingbox are also compared with the predictions made by a numerical study performed by nonlinear finite element analysis showing less than 5% difference in load-displacement behaviour and buckling load and full agreement in predicting the buckling mode shape.

show abstract

Section: Introductionmentioning

confidence: 84%

“…Therefore, there remains scope for improvement in buckling and postbuckling behaviour for this wingbox, as discussed by Liguori et al (12) The design process of the wingbox is elaborated with more details in Ref. [11].…”

Section: Design and Manufacture Of The Wingboxmentioning

confidence: 99%

Static test of a variable stiffness thermoplastic composite wingbox under shear, bending and torsion

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The laminate stacking sequence is 45∕ − 45∕45∕ − 45∕ 90∕0 1∕2 S , which is the same as that used for the skin of the 3BW presented in Ref. [20]. Figure 14 shows the nominal thickness variation of the laminate, which is obtained with the procedure presented in Sec.…”

Section: A Finite Element Modelingmentioning

confidence: 99%

“…In fact, in composite laminates, an effective way to change their stiffness in the vicinity of cutouts is represented by tailoring it via tow steering. This technology has been widely studied in recent decades to improve the structural performance of composite laminates, including buckling [17][18][19] and postbuckling [20][21][22]. Indeed, work dealing with tow steering to enhance buckling and postbuckling responses, as well as ultimate failure loads of panels with cutouts, can be found in Refs.…”

mentioning

confidence: 99%

Continuous Tow Steering Around an Elliptical Cutout in a Composite Panel

Zucco¹,

Rouhi²,

Oliveri³

et al. 2021

AIAA Journal

Self Cite

View full text Add to dashboard Cite

Cutouts are widely used to accommodate windows, openings for access purposes, or fasteners in the primary structural parts of airplanes. The presence of cutouts in composite panels results in stress or strain concentrations, leading to potentially reduced load-carrying capacity. Steering tows around cutouts using emerging techniques in three-dimensional (3-D) printing and advanced fiber placement can potentially alleviate such problems. Continuous tow steering around cutouts also eliminates fiber cutting, thereby precluding ply-level 3-D stress concentration, which could otherwise lead to delamination-induced damage. This work examines stress and strain concentrations, using continuous tow steering, around a representative wingbox access hole. Buckling response under compression loading together with stress and strain concentrations under both tensile and compression loads are examined. A steered configuration shows a 26% improvement in buckling performance in comparison with the equivalent straight-fiber configuration. Under tensile loading, the maximum stress and strain concentration factors around the cutout are 29 and 32% larger, respectively, for straight-fiber orientations than those with steered tows around the cutout. For the compression loading condition, the direct strain of the panel with straight-fiber orientations was found to be three times that of steered-fiber trajectories in the vicinity of the cutout.

show abstract

“…In [4] the authors show that a steered layup leads to an inhomogeneous temperature distribution over the roller width, which is why the in-situ processing window is hard to meet entirely in a complex laminate. Consistently, in-situ consolidation was so far successfully shown only for rather simple geometries, such as for example a booster casing [5] and a wing box demonstrator [6]. Also, in-situ layup requires the use of an expensive, high-quality tape material [7,8].…”

Section: Introductionmentioning

confidence: 99%

Effects of defects on laminate quality and mechanical performance in thermoplastic Automated Fiber Placement-based process chains

Zenker

Bruckner

Drechsler

2019

Advanced Manufacturing: Polymer & Composites Science

View full text Add to dashboard Cite

Automated Fiber Placement of thermoplastic unidirectional tape materials offers several advantages over conventional organosheets, such as enhanced part performance through tailored fiber architecture, and economic and ecological benefits due to scrap reduction. Because material is cut perpendicular to the feeding direction in state-of-the-art machine technology, triangular gaps and overlaps occur when geometrically complex layups are fabricated. Their effect on part properties is unknown for thermoplastic materials. This study investigates the influence of various defect configurations on laminate quality and mechanical performance for different consolidation processes. Analysis of microsections prepared from post-consolidation specimens shows out-of-plane undulations in defect areas. The undulation extent is quantified by angle and deflection. Tensile and compressive testing is performed. Gaps reduce ultimate tensile and compressive strength significantly for variothermal press and autoclave consolidation. Digital-image-correlation-based strain measurement during tensile testing shows strain concentration in the defect area for these specimens. Specimens consolidated in an isothermal stamp forming process show no comparable stress concentration, as well as no reduced ultimate strength. Specimens containing overlaps generally show a better performance in terms of ultimate strength compared to those containing gaps. Even though no full factorial design of experiments was used, the results obtained from this study can be used as a baseline for sector-boundary design strategies. The definition of defect-specific knock-down factors would be a next step towards the solid engineering of thermoplastic Automated Fiber Placement parts.

show abstract

Design, Manufacture and Test of an In-Situ Consolidated Thermoplastic Variable-Stiffness Wingbox

Cited by 38 publications

References 28 publications

Static test of a variable stiffness thermoplastic composite wingbox under shear, bending and torsion

Static test of a variable stiffness thermoplastic composite wingbox under shear, bending and torsion

Continuous Tow Steering Around an Elliptical Cutout in a Composite Panel

Effects of defects on laminate quality and mechanical performance in thermoplastic Automated Fiber Placement-based process chains

Contact Info

Product

Resources

About