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The dynamic stability problem of composite annular plates with auxetic properties

Pawlus Dorota

Engineering Transactions

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2023

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Vol. 71, iss. 3

329--349

EN

This paper presents the effect of the auxeticity on the behaviour of a plate subjected to the loss of stability. The plate structure is composed of three layers built of auxetic or conventional facings and a conventional core. The plate is loaded mechanically in the plane of facings with forces increasing in time. The main technique of the problem solution is based on the orthogonalisation and finite differences methods. Selected examples of plates were calculated with the use of the finite difference method. The obtained results allow observing the similarities and differences between plate models, whose structures are built of conventional layers or mixed layers: auxetic-foam-auxetic. Investigations complement the knowledge of the responses of the composite structures with auxetic properties. They show the possibility of using special plate structures whose materials are characterised by the negative value of Poisson’s ratio.

2

Stability state evaluation of composite three-layered annular plates with asymmetrical damage

Pawlus Dorota

Archive of Mechanical Engineering

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2019

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Vol. LXVI, nr 1

39--58

EN

The paper presents the response of a three-layered annular plate with damaged laminated facings to the loads acting in their planes. The presented problem concerns the analysis of the combination of global plate failure in the form of buckling with the local micro defects, like fibre or matrix cracks, located in the laminas. The plate structure consists of thin laminated, fibre-reinforced composite facings and a thicker foam core. The matrix and fibre cracks of facings laminas can be transversally symmetrically or asymmetrically located in plate structure. Critical static and dynamic stability analyses were carried out solving the problem numerically and analytically. The numerical results show the static and dynamic stability state of the composite plate with different combinations of damages. The final results are compared with those for undamaged structure of the plate and treated as quasi-isotropic ones. The analysed problem makes it possible to evaluate the use of the non-ideal composite plate structure in practical applications.

3

Dynamic Response of Three-Layer Annular Plate with Damaged Composite Facings

Pawlus D.

Archive of Mechanical Engineering

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2018

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Vol. LXV, nr 1

83--105

EN

The paper presents the dynamic behaviour of three-layer annular plates with damaged facings. The plate is composed of thin laminated, fibre-reinforced composite facings and thicker, foam core. Failure of the plate facings is modelled as fibre or matrix cracks. The plate loaded in the plane of facings with quickly increasing radially compressed forces loses its dynamic stability. Evaluation of the critical state of the plate with failures was carried out using both analytical and numerical solutions. The comparison of results between plates with material properties treated as isotropic, quasi-isotropic and composite has been conducted. Presented tables and figures create the image of dynamic responses of examined composite plates with structure failures.

4

Evaluation of critical static loads of three-layered annular plate with damaged composite facings

Pawlus D.

Engineering Transactions

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2016

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Vol. 64, iss. 4

613--619

EN

This paper presents the approach to evaluate the critical, static loads of three-layered annular plate with composite facings whose laminas are damaged. The plate is composed of thin, laminated fibre-reinforced composite facings and a thicker, foam core. The fibre and matrix cracks of facing laminas influence the plate critical state. The solution of such buckling problem was carried out using both analytical and numerical methods. Axisymmetrical and asymmetrical plate buckling modes were analysed. Numerous results show the stability behaviour of composite plate with failures.