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A Modal Interface Theory for Component-based Design

Raclet J. B., Benveniste A., Legay A., Badouel E., Caillaud B., Passerone R.

Fundamenta Informaticae

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2011

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Vol. 108, nr 1/2

119-149

EN

This paper presents the modal interface theory, a unification of interface automata and modal specifications, two radically dissimilar models for interface theories. Interface automata is a game-basedmodel, which allows the designer to express assumptions on the environment and which uses an optimistic view of composition: two components can be composed if there is an environment where they can work together. Modal specifications are a language theoretic account of a fragment of the modal mu-calculus logic with a rich composition algebra which meets certain methodological requirements but which does not allow the environment and the component to be distinguished. The present paper contributes a more thorough unification of the two theories by correcting a first attempt in this direction by Larsen et al., drawing a complete picture of the modal interface algebra, and pushing the comparison between interface automata, modal automata and modal interfaces even further. The work reported here is based on earlier work presented in [41] and [42].

2

The analytical study on the optimal ballistic performance using interface theory

Hegde G. S., Narasimha Murthy H. N., Krishna M.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 41, nr 1-2

112-123

EN

Purpose: Analytical determination of impact velocity for different combination of target and projectile materials is the objective of this paper. Design/methodology/approach: The penetration efficiency is maximum when the interaction between the projectile and target is hydrodynamic. Considering zero strength for target and projectile the hydrodynamic impact velocities are predicted using hydrodynamic equation of state. Findings: The hydrodynamic equation being an indeterminate equation is solved using interface theory (briefed in the appendix). The indeterminate Johnson-Cook (JC) model and Steinberg-Guinian (SG) model are also solved using interface theory to predict the influence of static strength of projectile and thermal softening effects. It is inferred that the penetration efficiency decreases with increasing static strength of target and also due to thermal softening of the projectile. In the process the plastic strain, the strain rate and the increase in temperature during impact are theoretically predicted. The segmented projectiles have less/more penetration efficiency than the monolithic impactors and hence require higher/lower impact velocities nearing to hydrodynamic state. Research limitations/implications: The analytical results obtained are in fair agreement with experimental results obtained in the reviewed literatures. Some contrasts are also observed. Originality/value: The paper present the analytical study on the optimal ballistic performance using interface theory.

3

Interface driven optimisation of springback in stretch bending of autobody panels

Hedge G.S., Shivaprasad J., Sridhar R.

Archives of Computational Materials Science and Surface Engineering

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2009

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Vol. 1, nr 3

168-173

EN

Purpose: Analytical determination of springback in the stretch bending of autobody double curved panels and optimization of parameters like yield strength and thickness of plate, have been the prime purposes of this paper. Design/methodology/approach: The elasto plastic behaviour governed by Hooke's law and Holomann's law, has been solved using interface theory, the original contribution of author. In the process Hegde's interface modulus has been coined, which depends on both modulus of elasticity and the plastic coefficient. Findings: The linearized functions of change of springback and stretch tension are solved for optimization, again using interface theory briefed in the Appendix. Practical implications: The published models of springback optimization being complicated, a need has been felt to formulate computationally easy and confidently accurate model of springback determination. The theoretical deliberations are demonstrated on materials based on the data obtained from the published references. Originality/value: The authors are confident of the originality and do claim authentically the novelty in the workout of the analysis. The interface theory applied at several stages in the analysis gives the optimal solutions to variables in the hyperspace defined by a linear system with redundancy in unknown variables.

4

Hedge's instability mechanics for the prediction of forming limit in sheet metal forming

Hedge G.S., Nataraj J.R., Sridhar R.

Archives of Computational Materials Science and Surface Engineering

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2009

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Vol. 1, nr 3

155-160

EN

Purpose: The purpose of the paper is to investigate the Hegde's instability mechanics for the prediction of forming limit in sheet metal forming. Design/methodology/approach: Hegde's Instability Mechanics (HIM) paves way for explaining the effects of diffuse instability and localization due to necking in sheet metal forming. For different ranges of stress ratios, the ratio of strain differentials has been computed and hence the forming limits are predicted. Findings: Basing the formulation of HIM on the von Misess yield criterion and applying the interface theory (briefed in appendix) the state-of-the-art purpose is deemed to be well served and demonstrated. Interface theory to explain in simple terms, gives the optimal decision variables in an 'n' dimensional hyper-space. The concept of HIM is demonstrated on isotropic and anisotropic materials. The anisotropic materials show better stability than isotropic materials in sheet metal forming. However the geometric instability is analyzed with the assumptions that the thickness stresses are negligible and biaxial state of stress persists in sheet metal forming. Practical implications: The observations are based on the theoretical findings for which the experimental validation exists in the reviewed references. Originality/value: To the sincere knowledge of authors, is both different and unique of its kind in sheet forming mechanics needing horizontal exploration by potential researchers.