Thermomechanical problem

It should be emphasized that in all these cases, combined or superimposed phenomena must be dealt with, viz. for stage IV, fluiddynamics, kinetics of polymerization, and rheokinetic changes caused by chemical reactions for stage V, polymerization kinetics, crystallization kinetics and heat transfer effects a thermomechanical problem in combination with crystallization kinetics. Construction of a mathematical model requires simultaneous solution of a set of equations in order to describe these related phenomena. 

Fig. 7 The small-scale yielding problem in which crazing is allowed along the crack symmetry plane with a plastic bulk. The boundary conditions of the coupled thermomechanical problem are reported from [22,57]...

The most widely researched technology today is that of the inverted SOFC cell, which is why most laboratories working on the topic use work done on SOFC. But research performed by Julich and at Domier in Germany in the 1990s shows that the thermomechanical problems related to the use of ceramics will confine this technology to low power applications (<100kW). 

As the figure depicts many features of the actual experiments, such as buckling, folding, and wavy shape of the side walls, can be successfully predicted for this coupled thermomechanical problem. 

The automotive industry needs more and more organic material with improved thermomechanical properties up to 200-220°C, but the requirements for the processability and cost make die problem difficult to solve. The development of new... 

Abstract In this contribution, the coupled flow of liquids and gases in capillary thermoelastic porous materials is investigated by using a continuum mechanical model based on the Theory of Porous Media. The movement of the phases is influenced by the capillarity forces, the relative permeability, the temperature and the given boundary conditions. In the examined porous body, the capillary effect is caused by the intermolecular forces of cohesion and adhesion of the constituents involved. The treatment of the capillary problem, based on thermomechanical investigations, yields the result that the capillarity force is a volume interaction force. Moreover, the friction interaction forces caused by the motion of the constituents are included in the mechanical model. The relative permeability depends on the saturation of the porous body which is considered in the mechanical model. In order to describe the thermo-elastic behaviour, the balance equation of energy for the mixture must be taken into account. The aim of this investigation is to provide with a numerical simulation of the behavior of liquid and gas phases in a thermo-elastic porous body. 

In the following investigation, we use this theory allowing a continuum thermomechanical approach to the two-phase flow problem in a porous solid. The transient and stationary motion of liquids in porous solids with small pores is complex and not all related problems have been solved yet. The main internal... 

As a first incursion into the thermomechanical analysis of the problem, we present recent results [57] in which only thermoplastic effects are accounted for. The related temperature variations appear larger than those from thermoelastic effects, and are expected to be of major importance in the competition between shear yielding and crazing. The influence of thermoelastic effects will be briefly discussed at the end of this section. 

While TMA is one of the older and simpler forms of thermal analysis, its importance is in no way diminished by its age. Advances in DSC technology and the appearance of dynamic mechanical analysis (DMA) as a common analytical tool have decreased the use of it for measuring glass transitions, but nothing else allows the measurement of CTE as readily as TMA. In addition, the ability to run standardized material test methods at elevated temperatures easily makes TMA a reasonable alternative to larger mechanical testers. As the electronic, biomedical, and aerospace industries continue to push the operating limits of polymers and their composites, this information will become even more important. During the last 5 years a major renewed interest in dilatometry and volumetric expansion has been seen. Other thermomechanical techniques will also likely be developed or modernized as new problems arise. 

Next, we consider an application related to the paper making process and study a water allocation problem for an integrated plant containing a thermomechanical pulping plant and a paper mill. For details of this problem with three objectives, see Hakanen et al. (2004). 

Reading, M. and Haines, P.J., Thermomechanical, dynamic mechanical and associated methods, in Thermal Methods of Analysis Principles, Applications and Problems, Haines, P.J., Ed., Blackie Academic and Professional, Glasgow, U.K., 1995. 

The objective of this work has been the development of finite element algorithms for hydraulically coupled three-dimensional thermomechanical processes to be applied to geological problems. A further aim was the realization of couplings to existing finite element algorithms for... 

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