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Stress and failure analysis of composite plates with circular hole subjected to shear loading. Part 1, Analytical and finite element formulation

Khechai Abdelhak, Tati Abdelouahab, Belarbi Mohamed-Ouejdi, Rekbi Fares Mohammed Laid

Composites Theory and Practice

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2022

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R. 22, nr 4

205--210

EN

This current paper, which is the first part of two parts of a complete article, presents the theoretical and finite element formulation developed and proposed by the authors to obtain the stress concentration factors (SCFs) and the first ply failure (FPF) loads of composite laminated plates. The numerical studies are performed using a quadrilateral finite element of four nodes with thirty-two degrees of freedom. The present finite element was previously developed by the authors to study the bending and buckling of composite plates. The present finite element is a combination of two finite elements. The first one is a linear isoparametric membrane element, and the second one is a high-precision rectangular Hermitian element. In the second part of the paper, several examples will be considered to demonstrate and affirm the accuracy and the performance of the present element, as well as highlight the effect of some parameters on the stress distribution. The FPF strengths and their locations in laminated plates with and without holes are calculated by adapting the Hashin-Rotem, Tsai-Hill, and Tsai-Wu failure theories.

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Stress and failure analysis of composite plates with a circular hole subjected to shear loading. Part 2, Results and discussions

Khechai Abdelhak, Tati Abdelouahab, Belarbi Mohamed-Ouejdi, Rekbi Fares Mohammed Laid

Composites Theory and Practice

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2022

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R. 22, nr 4

225--232

EN

This paper, the second part of two parts of a complete paper, presents the analytical and numerical results of stresses around circular cutouts in anisotropic and isotropic plates under shear loading. The main aim of this study is to understand the effect of the presence of cutouts on the stress concentration and failure mechanisms in composite laminates. The numerical investigations are performed by means of the quadrilateral finite element of four nodes with thirty-two degrees of freedom. The present finite element is a combination of two finite elements. The first one is a simple linear isoparametric membrane element and the second one is a high-precision rectangular Hermitian element. The analytical and finite element formulations were presented in the first part of the paper. Several new examples are considered to demonstrate and affirm the accuracy and the performance of the present element and to highlight the effect of some parameters on the stress distributions. The numerically obtained results are found to be in good agreement with the analytical findings. On the other hand, first ply failure (FPF) strengths in laminates with and without holes are calculated by adapting the Hashin-Rotem, Tsai-Hill, and Tsai-Wu failure theories. Finally, the numbers of the figures are obtained, using various E1/E2 ratio values, for the maximum positive and negative stresses values located in the vicinity of the cutout versus the angular location of points, and for various fiber orientation angles.

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Charakterystyka konstrukcyjna i techniczna budynków pasywnych i plus energetycznych

Bil Agnieszka

Technika Chłodnicza i Klimatyzacyjna

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2019

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nr 1-2

12--18

PL

W dobie dużego nacisku na ochronę środowiska, zdegradowanego przede wszystkim przez szeroko rozwinięty przemysł, zrodziła się idea powstania budynków o klasach energetycznych określanych jako budynki pasywne oraz plus energetyczne. Charakteryzują się one niskim wskaźnikiem sezonowego zapotrzebowania na ciepło, dzięki zastosowaniu w ich konstrukcji wielu metod termomodernizacji, pozwalających uzyskać izolację termiczną o wysokim oporze cieplnym. Ich systemy energetyczne oparte są na pozyskiwaniu energii cieplnej ze źródeł niekonwencjonalnych. W artykule przedstawiona została charakterystyka konstrukcyjno-budowlana i instalacyjno- techniczna takich budynków.

EN

Nowadays, when environmental protection is one of the key issues, the concept of passive buildings and plus-energetic buildings has become very attractive. These buildings have low seasonal heat demand thanks to thermomodernization solutions applied for better thermal insulation and heating systems based on non-conventional energy sources. Design and technical characteristics of such buildings are presented in the paper.

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Razruszenije anizotropnych plastinok s ostrougolenymi otverstijami

Bożidarnik V., Sulim G.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Mechanika

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2001

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Z. 73

289-296

EN

A limiting loading and an angle of an initial crack growth direction from a hole's sharprecovery point in an anisotropic plate under an all-round bending are examined. It is considered, that the crack grows in a direction of greatest possible damage ratio in a prefracture zone, defined by the stress intensity factors of circular stress and a fracture toughness of a material at the moment ehen damage ratio achieves a critical value.