Search results

1 – 10 of over 8000
To view the access options for this content please click here
Article
Publication date: 23 August 2013

Rosario Borrelli, Francesco Di Caprio, Umberto Mercurio and Fulvio Romano

The main objective of this work is to assess the current capabilities of different commercial finite element (FE) codes in simulating the progressive damage of composite…

Abstract

Purpose

The main objective of this work is to assess the current capabilities of different commercial finite element (FE) codes in simulating the progressive damage of composite structures under quasi-static loading condition in post-buckling regime.

Design/methodology/approach

Progressive failure analysis (PFA) methodologies, available in the investigated FE codes, were applied to a simple test case extracted from literature consisting in a holed composite plate loaded in compression.

Findings

Results of the simulations are significantly affected by the characteristic parameters needed to feed the degradation models implemented in each code. Such parameters, which often do not have a physical meaning, have to be necessarily set upon fitting activity with an experimental database at coupon level. Concerning the test case, all the codes were found able to capture the buckling load and the failure load with a good accuracy.

Originality/value

This paper would to give an insight into the PFA capabilities of different FE codes, providing the guidelines for setting the degradation model parameters which are of major interest.

Details

International Journal of Structural Integrity, vol. 4 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

To view the access options for this content please click here
Article
Publication date: 12 June 2017

Farshad Hashemi Rezvani, Behrouz Behnam, Hamid Reza Ronagh and M. Shahria Alam

The purpose of this paper is to determine the failure progression resistance of the steel moment-resisting frames subjected to various beam-removal scenarios after…

Abstract

Purpose

The purpose of this paper is to determine the failure progression resistance of the steel moment-resisting frames subjected to various beam-removal scenarios after application of the design earthquake pertinent to the structure by investigating a generic eight-story building.

Design/methodology/approach

The structure is first pushed to arrive at a target roof displacement corresponding to life safety level of performance. To simulate the post-earthquake beam-removal scenario, one of the beam elements is suddenly removed from the structure at a number of different positions. The structural response is then evaluated by using nonlinear static and dynamic analyses.

Findings

The results show that while no failure is observed in all of the scenarios, the vulnerability of the upper stories is much greater than that of the lower stories. In the next step, the structural resistance to such scenarios is determined. The results confirm that for the case study structure, at most, the resistance to failure progression in upper stories is 58 percent more than that of lower stories.

Originality/value

Failure and fracture of beam-to-column connections resulting in removal of beam elements may lead to a chain of subsequent failures in other structural members and eventually lead to progressive collapse in some cases. Deficiency in design or construction process of structures when combined by application of seismic loads may lead to such an event.

Details

International Journal of Structural Integrity, vol. 8 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

To view the access options for this content please click here
Article
Publication date: 9 April 2021

Ashok Magar and Achchhe Lal

The prediction of accurate failure strength and a composite laminate failure load is of paramount importance for reliable design. The progressive failure analysis helps to…

Abstract

Purpose

The prediction of accurate failure strength and a composite laminate failure load is of paramount importance for reliable design. The progressive failure analysis helps to predict the ultimate failure strength of the laminate, which is more than the first ply failure (FPF) strength. The presence of a hole in the laminate plate results in stress concentration, which affects the failure strength. The purpose of the current work is to analyze the stress variation and progressive failure of a symmetric laminated plate containing elliptical cutouts under in-plane tensile loading. The effect of various parameters on FPF and last ply failure (LPF) strength is studied.

Design/methodology/approach

The ply-by-ply stresses around elliptical cutouts are obtained analytically using Muskhelishvili's complex variable formulation. To predict the progressive failure, Tsai–Hill (T-H) and Tsai–Wu (T-W) failure criteria are used, and depending on the mode of failure, lamina modulus is degraded.

Findings

The study has revealed that fiber orientation and stacking sequence for given loading have the most significant effect on the laminate's failure strength.

Originality/value

Complex variable method and conformal mapping are simple and proficient for studying failure analysis of a laminated plate with elliptical cutout.

Details

International Journal of Structural Integrity, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1757-9864

Keywords

To view the access options for this content please click here
Article
Publication date: 14 September 2011

Shenyan Chen, M. Yasser, Zhiwei Lin, Hai Huang and Xianzhu Liang

Aimed at the complex failure modes of composite pi joint, the material elastic modulus degradation method was applied to simulate the progressive failure procedure. A…

Abstract

Aimed at the complex failure modes of composite pi joint, the material elastic modulus degradation method was applied to simulate the progressive failure procedure. A three-dimensional finite element model of one type composite pi joint was established based on the commercial finite element software Abaqus. Two progressive failure analysis subroutines considering both the composite laminates and adhesive failures were developed within Abaqus/Standard. One of them is based on Hashin three-dimensional failure criteria and Ye-delamination criterion to distinguish five failure modes of composite laminates: fiber breakage, fiber buckling, matrix tensile cracking, matrix compression, and delamination failure. The other is based on Tsai-Wu criterion to discriminate the composite failure. Additionally, an elastic-perfectly plastic material model was applied in the subroutines to simulate the adhesive failure. The established pi joint model was analyzed under given increasing tensile loads. The numerical results show that the proposed method is effective in predicting initial failure position, initial failure load, final failure load and failure modes for the present composite pi joint.

Details

World Journal of Engineering, vol. 8 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

To view the access options for this content please click here
Article
Publication date: 18 April 2017

Hongxiang Tang, Yuhui Guan, Xue Zhang and Degao Zou

This paper aims to develop a finite element analysis strategy, which is suitable for the analysis of progressive failure that occurs in pressure-dependent materials in…

Abstract

Purpose

This paper aims to develop a finite element analysis strategy, which is suitable for the analysis of progressive failure that occurs in pressure-dependent materials in practical engineering problems.

Design/methodology/approach

The numerical difficulties stemming from the strain-softening behaviour of the frictional material, which is represented by a non-associated Drucker–Prager material model, is tackled using the Cosserat continuum theory, while the mixed finite element formulation based on Hu–Washizu variational principle is adopted to allow the utilization of low-order finite elements.

Findings

The effectiveness and robustness of the low-order finite element are verified, and the simulation for a real-world landslide which occurred at the upstream side of Carsington embankment in Derbyshire reconfirms the advantages of the developed elastoplastic Cosserat continuum scheme in capturing the entire progressive failure process when the strain-softening and the non-associated plastic law are involved.

Originality/value

The permit of using low-order finite elements is of great importance to enhance computational efficiency for analysing large-scale engineering problems. The case study reconfirms the advantages of the developed elastoplastic Cosserat continuum scheme in capturing the entire progressive failure process when the strain-softening and the non-associated plastic law are involved.

Details

Engineering Computations, vol. 34 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

To view the access options for this content please click here
Article
Publication date: 1 July 2014

Fábio Ribeiro Soares da Cunha, Tobias Wille, Richard Degenhardt, Michael Sinapius, Francisco Célio de Araújo and Rolf Zimmermann

This paper aims to present a new robustness-based design strategy for thin-walled composite structures under compressive loading, which combines strength requirements in…

Abstract

Purpose

This paper aims to present a new robustness-based design strategy for thin-walled composite structures under compressive loading, which combines strength requirements in terms of the limit and ultimate load with robustness requirements evaluated from the structural energy until collapse.

Design/methodology/approach

In order to assess the structural energy, the area under the load-shortening curve between several characteristic points such as local buckling, global buckling, onset of degradation and collapse load is calculated. In this context, a geometrically nonlinear finite element analysis is carried out, in which the ply properties are selectively degraded by progressive failure.

Findings

The advantage of the proposed methodology is observed by analyzing unstiffened composite plates under compressive loading, wherein the lightest plate that satisfies both strength and robustness requirements can be attained.

Practical implications

As a practical implication, this methodology gives a new argument to accept the collapse load close to the ultimate load once robustness is ensured.

Originality value

The structural energy is employed to investigate the robustness of thin-walled composite structures in postbuckling, and new energy-based robustness measures are proposed. In the design of composite structures, this innovative strategy might lead to a more robust design when compared to an approach that only accounts for the ultimate load.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 86 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

To view the access options for this content please click here
Article
Publication date: 21 June 2013

Osama Bedair

The paper aims to review recent developments for analysis of deteriorating stiffened panels subjected to static and explosive forces.

Abstract

Purpose

The paper aims to review recent developments for analysis of deteriorating stiffened panels subjected to static and explosive forces.

Design/methodology/approach

The first part reviews numerical procedures developed for stiffened panels subjected to explosive forces. The structural idealization, the theoretical basis, and the merits of these methods are discussed. The second part reviews the probabilistic procedures developed for analysis of deteriorating stiffened panels. The third part reviews recent work developed in several finite element modelling philosophies for analysis of stiffened panels. The influence of various parameters affecting the structural performance, such as geometric and material imperfections, corrosion, residual stresses, etc. is discussed. The fourth part reviews hybrid procedures developed to provide approximate solutions for the designers. Numerical procedure is presented using combination of energy formulations and mathematical programming techniques to model the interaction between the box girder components.

Findings

Localized damage largely affects the performance of stiffened panels and must be accounted for in the design phase. Little emphasis was given in the published literature to developing simplified analytical models that can be used in practice to compute the residual strength of the stiffened panels under these types of loadings. Furthermore, analytical expressions are required to compute the reduction in the stiffness induced due to the structural or material defects. These expressions must be dependent on the type of damage. It must be noted that some of this damages is localized in nature and must be accounted for by using specialized functions to assess the structural defect accurately. Research work is required in this direction.

Practical implications

The paper provides useful resource material for the engineers in practice regarding recent techniques developed to assess damaged stiffened panels subject to static and explosive loadings. The paper reviews work developed over the past 20 years that can be used as a baseline for future developments.

Originality/value

Very limited literature dealt with the ultimate strength of damaged stiffened structure under static and explosive forces. No guidelines are available in current design codes to assess the damage in predicting the strength of deteriorating stiffened panels.

Details

Multidiscipline Modeling in Materials and Structures, vol. 9 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

To view the access options for this content please click here
Article
Publication date: 17 October 2018

Jiang Xie, Haolei Mou, Xuan Su and Zhenyu Feng

This paper aims to present an evaluation method for energy-absorption characteristics of thin-walled composite structures with random uncertain parameters.

Abstract

Purpose

This paper aims to present an evaluation method for energy-absorption characteristics of thin-walled composite structures with random uncertain parameters.

Design/methodology/approach

The mechanical properties of T700/3234 are obtained by material performance tests and energy-absorption results are obtained by quasi-static crushing tests of thin-walled composite circular tubes. The indicators of triggering specific load (TSL) and specific energy absorption (SEA) are introduced and calculated to determine the energy-absorption characteristics and validate the probability finite element analysis model. The uncertainty in the parameters contain the machining tolerance for the thickness and inner diameter of composite circular tubes and are associated with the composite material system. The Plackett–Burman method is used to choose the measurement parameters. Then, the response surface method is used to build a second-order function of random uncertain parameters versus TSL/SEA, and the Monte Carlo method is finally used to obtain the probabilities of TSL and SEA.

Findings

The finite element models can accurately simulate the initial peak load, load-displacement curve and SEA value. The random uncertain parameter method can be used to evaluate the energy-absorption characteristics of thin-walled composite circular tubes.

Practical implications

The presented evaluation method for energy-absorption characteristics of thin-walled composite structures is an approach that considers uncertain parameters to increase the simulation accuracy and decrease the computational burden.

Originality/value

This methodology considers uncertain parameters in evaluating the energy-absorption characteristics of thin-walled composite structures, and this methodology can be applied to other thin-walled composite structures.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 8
Type: Research Article
ISSN: 1748-8842

Keywords

To view the access options for this content please click here
Article
Publication date: 10 August 2015

Mica Grujicic, Jennifer Snipes, Ramin Yavari, S. Ramaswami and Rohan Galgalikar

The purpose of this paper is to prevent their recession caused through chemical reaction with high-temperature water vapor, SiC-fiber/SiC-matrix ceramic-matrix composite…

Abstract

Purpose

The purpose of this paper is to prevent their recession caused through chemical reaction with high-temperature water vapor, SiC-fiber/SiC-matrix ceramic-matrix composite (CMC) components used in gas-turbine engines are commonly protected with so-called environmental barrier coatings (EBCs). EBCs typically consist of three layers: a top thermal and mechanical protection coat; an intermediate layer which provides environmental protection; and a bond coat which assures good EBC/CMC adhesion. The materials used in different layers and their thicknesses are selected in such a way that the coating performance is optimized for the gas-turbine component in question.

Design/methodology/approach

Gas-turbine engines, while in service, often tend to ingest various foreign objects of different sizes. Such objects, entrained within the gas flow, can be accelerated to velocities as high as 600 m/s and, on impact, cause substantial damage to the EBC and SiC/SiC CMC substrate, compromising the component integrity and service life. The problem of foreign object damage (FOD) is addressed in the present work computationally using a series of transient non-linear dynamics finite-element analyses. Before such analyses could be conducted, a major effort had to be invested toward developing, parameterizing and validating the constitutive models for all attendant materials.

Findings

The computed FOD results are compared with their experimental counterparts in order to validate the numerical methodology employed.

Originality/value

To the authors’ knowledge, the present work is the first reported study dealing with the computational analysis of the FOD sustained by CMCs protected with EBCs.

Details

Multidiscipline Modeling in Materials and Structures, vol. 11 no. 2
Type: Research Article
ISSN: 1573-6105

Keywords

To view the access options for this content please click here
Article
Publication date: 1 July 2014

Fábio Ribeiro Soares da Cunha, Tobias Wille, Richard Degenhardt, Michael Sinapius, Francisco Célio de Araújo and Rolf Zimmermann

– The purpose of this paper is to present the probabilistic approach to a new robustness-based design strategy for thin-walled composite structures in post-buckling.

Abstract

Purpose

The purpose of this paper is to present the probabilistic approach to a new robustness-based design strategy for thin-walled composite structures in post-buckling.

Design/methodology/approach

Because inherent uncertainties in geometry, material properties, ply orientation and thickness affect the structural performance and robustness, these variations are taken into account.

Findings

The methodology is demonstrated for the sake of simplicity with an unstiffened composite plate under compressive loading, and the probabilistic and deterministic results are compared. In this context, the structural energy and uncertainties are employed to investigate the robustness and reliability of thin-walled composite structures in post-buckling.

Practical implications

As practical implication, the methodology can be extended to stiffened shells, widely used in aerospace design with the aim to satisfy weight, strength and robustness requirements. Moreover, a new argument is strengthened to accept the collapse close to ultimate load once robustness is ensured with a required reliability.

Originality/value

This innovative strategy embedded in a probabilistic framework might lead to a different design selection when compared to a deterministic approach, or an approach that only accounts for the ultimate load. Moreover, robustness measures are redefined in the context of a probabilistic design.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 86 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

1 – 10 of over 8000