Analysis of Thermoplastic Structures

conference paper

English

It has been appeared during the use of the thermoplastic structures, that the influence of the time-factor is underestimated as a result of ignorance of material behaviour. Therefore, the natural requirement of the praxis is to analyse the functionality of the plastic structure during its lifetime in more details. It is necessary to consider the material behaviour with regard to time-dependent factors in the analysis, namely carrying capacity, creep, stress relaxation, shrinkage, swelling and influence of radiation, manufacturing technology, the residual stress, the influence of the environment, coupling method etc. It depends on the material selection and the suitability of usage. Subsequently, it is necessary to implicate loading states in the solution, especially change in temperature, magnitude and direction of load, time action, manufacturing phase etc. and to evaluate thermoplastic structures to the adverse reaction of the combination of load states. Consequently, it is necessary to consider influence on applicability of designing the geometrical shape of the structure, construction details, coupling technology, effect boundary conditions, for example the effect of subsoil etc. It is necessary to deal with physically and geometrically non-linear calculations, stress influence on the structures stiffness, contact problems, stability solution, optimising etc. Three-dimensional models of the constructions are used for the analyses of the thermoplastic structures. The ANSYS program system appears convenient for the analysis. It enables to analyse time-depending behaviour of the plastic materials in the calculations. The thermoplastic structures are evaluated according to some criteria, such as limit conditions of material models, deflections, stability, lifetime, fatigue etc. Generally, time and magnitude load, temperature, influence of environment, style of coupling etc. are considered. The opinion that the plastic materials are convenient only for structures which are loaded adequately and which are used in certain environmental conditions has been thus confirmed.

Analysis, Thermoplastic, Structures

GRATZA, R., KYTÝR, J.

20. 11. 2003

Brno

80-214-2506-7

2nd PhD Workshop

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