Evaluation of fastener stiffness modelling methods for aircraft structural joints

Chandregowda, Sunil; Reddy, Ganga Reddy Chinnappa

doi:10.1063/1.5029577

Cited by 13 publications

(15 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The BEAM stiffnesses were taken to be greater than the SAMPLE and BOX stiffnesses because the BEAM bolts were much larger. In agreement with [53], 10 3 N/mm and 10 6 N/mm were found to be extreme stiffness values and thus…”

Section: Identification Methodssupporting

confidence: 77%

“…A connector element has a longitudinal stiffness and a radial stiffness, like two springs oriented longitudinally and transversely to the bolt direction. Chandregowda and Reddy [53] modelled a shear lap joint with six bolts and considered the effect of the connector radial stiffness. They found that existing semiempirical equations gave very different stiffness estimations, which had a substantial effect on the load distribution on bolts.…”

Section: Motivationmentioning

confidence: 99%

See 1 more Smart Citation

Testing Structural Elements under Multiaxial Loading: A Numerical Model of the Bench to Understand and Predict Complex Boundary Conditions

Grotto,

Peta,

Bouvet

et al. 2024

Aerospace

View full text Add to dashboard Cite

Airworthiness certification requires proof of structure strength, which is performed generally through a building block approach. To achieve this, representative intermediate-scale experiments generated by test benches are, in general, needed, in addition to material characterization on a coupons scale and structure testing on a large scale. The VERTEX test bench can generate the combined loading of tension/compression-shear-pressure on structural elements and was modelled with Finite Elements to perform virtual testing, representative of its intermediate-scale specificity. The numerous bolted joints of the bench were modelled and their behavior was identified in previous tests, so the model could quantitatively estimate the transfer function of the bench, which is the relationship between the displacements imposed by the jacks and the resulting loads on a given sample. The VERTEX model was identified to represent load shapes and amplitudes based on a training set and was later confronted by a validation set of tests of tension and shear. A model with ideal boundary conditions was also developed for a comparison, but it failed to predict some load shape specificities and did not give any indication of the loading amplitude. Application cases of the developed model are shown to assess a range of virtual testing possibilities.

show abstract

Section: Identification Methodssupporting

confidence: 77%

Section: Motivationmentioning

confidence: 99%

Testing Structural Elements under Multiaxial Loading: A Numerical Model of the Bench to Understand and Predict Complex Boundary Conditions

Grotto,

Peta,

Bouvet

et al. 2024

Aerospace

View full text Add to dashboard Cite

show abstract

“…A connector element has a longitudinal stiffness and a radial stiffness, like two springs oriented longitudinally and transversely to the bolt direction. Chandregowda and Reddy [53] modelled a shear lap joint with six bolts and considered the effect of the connector radial stiffness. They found that existing semi-empirical equations gave very different stiffness estimations, which had a substantial effect on the load distribution on bolts.…”

Section: Motivationmentioning

confidence: 99%

Testing Structural Elements under Multiaxial Loading: A Numerical Model of the Bench to Understand and Predict Complex Boundary Conditions

Grotto,

Peta,

Bouvet

et al. 2023

Preprint

View full text Add to dashboard Cite

Airworthiness certification requires proof of structure strength, which is performed generally through building block approach. To achieve this, representative intermediate scale experiments generated by test benches are in general needed, additionally to material characterization at coupons scale and structure testing at large scale. The VERTEX test bench can generate combined loading of tension/compression-shear-pressure on structural elements and was modelled with Finite Elements to perform virtual testing representative of its intermediate-scale specificity. The numerous bolted joints of the bench were modelled and their behavior identified in previous tests, so the model could quantitatively estimate the transfer function of the bench, which is the relation between the displacements imposed by the jacks and the resulting loads on a given sample. The VERTEX model was identified to represent load shapes and amplitudes on a training set, and was later confronted to a validation set of tests of tension and shear. A model with ideal boundary conditions was also developed for comparison but it failed to predict some load shape specificities and did not give any indication of loading amplitude. Application cases of the developed model are shown to assess a range of virtual testing possibilities.

show abstract

“…The base joint stiffness can be approximated using empirical calculations such as those outlined in the Douglas or Huth fastener models. 42 These empirical models are not directly applicable to the problem formulation presented in this methodology and may need to be adjusted to obtain more meaningful results during optimization. A bar element was used in this formulation; however, a similar derivation could be conducted for a beam element if the finite element model requires the restriction of rotational degrees of freedom.…”

Section: Multilayered Topology Optimizationmentioning

confidence: 99%

Part consolidation for additive manufacturing: A multilayered topology optimization approach

Crispo

Kim

2021

Numerical Meth Engineering

View full text Add to dashboard Cite

Part consolidation (PC) is becoming a viable cost savings approach due to the increased design freedom associated with industry adoption of additive manufacturing. However, there is little research focused on mathematical approaches for assembly level design generation, with most work aimed at providing best practices for merging several parts into one. This article presents a novel topology optimization approach to PC that determines the ideal number of parts, their geometry, and optimal joining pattern, without bias towards the original assembly. Multiple layered design domains are created, and a joining domain that determines the connections between parts is introduced. A multiobjective problem statement optimizes the complex trade-off between compliance, support structure volume, surface area, and number of joints, to minimize the total cost of the final assembly. Design variable initialization and boundary condition placement are discussed for problems with multiple domains. Three test cases are presented and solved for a range of cost trade-offs to demonstrate optimized solutions as design objectives are varied.

show abstract

Evaluation of fastener stiffness modelling methods for aircraft structural joints

Cited by 13 publications

References 6 publications

Testing Structural Elements under Multiaxial Loading: A Numerical Model of the Bench to Understand and Predict Complex Boundary Conditions

Testing Structural Elements under Multiaxial Loading: A Numerical Model of the Bench to Understand and Predict Complex Boundary Conditions

Testing Structural Elements under Multiaxial Loading: A Numerical Model of the Bench to Understand and Predict Complex Boundary Conditions

Part consolidation for additive manufacturing: A multilayered topology optimization approach

Contact Info

Product

Resources

About