Thermo-Mechanical Response

Fig. 18. Thermo-mechanical response of PVME hydrogels Ln gel length at 40 °C,...

Fig. 21. Thermo-mechanical response of fibrous PVME hydrogel...

Mol GN, Harris KD, Bastiaansen CM, Broer DJ. 2005. Thermo mechanical responses of liquid crystal networks with a splayed molecular organization. Adv Funct Mater 15 1155 1159. 

For evaluation of thermo-mechanical responses of the tested steel, compression tests were conducted on specimens machined from cast and wrought ingots of AISl M42 tool steel. 

K.X. Hu, C.P. Yeh, and K.W. Wyatt, Electro-Thermo-Mechanical Responses of Conductive Adhesive Materials, IEEE Transactions on Components Packaging and Manufacturing Technology, Part A, Vol 20, 1997, p 470-477... 

Liquid crystalline polymer composites have become an increasingly important material for technological field involving photonic applications. Several attractive features such as dielectric anisotropy present in the mesophase, reasonably wide temperature range, low thermal expansion coefficient, high chemical resistance, specific thermo-mechanical response etc. make them more attractive. Of comse several limitations have to overcome in order to avail the total benefit of using such materials for opto-electronic applications. 

The coupling effects of various poromechanical processes on the response of a porous medium have been successfully addressed by Biot s theory of poroelasticity and its extensions [3,4,5,8,2], The chemical effects have also been addressed by considering interaction between the porous matrix and a pore fluid comprising of a solute and solvent [10, 7, 6], Comprehensive anisotropic poromechanics formulations and corresponding solutions for the inclined borehole problem have been presented [4—2], However, the coupled chemo-thermo-hydro-mechanical response of an anisotropic porous medium has not been addressed to date. 

In this paper, the focus is on the development of a poromechanics model which addresses the chemical effects within the framework of the anisotropic porothermoelastic model [2], The resulting model, termed as porochemo-thermoelastic, accounts for fully coupled chemo-thermo-hydro-mechanical response of a chemically active formation saturated with a pore fluid comprising of two species under non-isothermal conditions. The numerical example presented demonstrates the thermo-chemical effect on the stress and pore pres-... 

Inorganic Gas response of polycrystalline semiconducting metal oxides Thermo-mechanical and thermo-chemical effects on percolation-dependent electron transport 41... 

Based on the characterization of the bentonite and on the details of the process of test installation, a thermo-hydro-mechanical model for the bentonite barrier and the heaters was to be prepared. Using this model, the thermo-hydro-mechanical response of the bentonite barrier as a result of the heat released by the heaters and the hydration from the host rock was required. Local field variables such as temperature, relative humidity, pore water pressure, stresses and displacements, as well as global... 

Abstract The Canadian Nuclear Safety Commission (CNSC) used the finite element code FRACON to perform blind predictions of the FEBEX heater experiment. The FRACON code numerically solves the extended equations of Biot s poro-elasticity. The rock was assumed to be linearly elastic, however, the poro-elastic coefficients of variably saturated bentonite were expressed as functions of net stress and void ratio using the state surface equation obtained from suction-controlled oedometer tests. In this paper, we will summarize our approach and predictive results for the Thermo-Hydro-Mechanical response of the bentonite. It is shown that the model correctly predicts drying of the bentonite near the heaters and re-saturation near the rock interface. The evolution of temperature and the heater thermal output were reasonably well predicted by the model. The trends in the total stresses developed in the bentonite were also correctly predicted, however the absolute values were underestimated probably due to the neglect of pore pressure build-up in the rock mass. 

The experiments conducted so far at the site in range of depths between 3000 and 3800 m show that hydraulic stimulation techniques can considerably increase the permeability in a rock volume that can extend up to several hundred meters around the well, thereby serving to establish connections between the wells. The major impact of the hydraulic stimulation could be explained by hydromechanical mechanisms (ruptures in fracture planes). However in the near well at the scale of some meters, a decrease of the impedancy is outlined via hydraulic vibration tests and is presently not well understood. As at this scale, the hydromechanical effect cannot be dissociated from the thermal effect due to the injection of a cold water in a hot media, the thermo-hydro-mechanical responses of the stimulated fractures must be investigated. 

Brazel, C.S. and Reppas, N.A. 1995. Thermo- and chemo- mechanically responsive polyfN-isopropylacryl-amide-co-methacrylic acid) hydrogels. Macrontolecules. 28 8016-8020. 

A Pasricha, M Tuttle and A Emery, Time-dependent response of IM7/5260 composites subjected to cyclic thermo-mechanical loading . Compos Sci Technol... 

Uny et also reported the chemical synthesis of protein polymers based on the (Val-Pro- Ala-Val-Gly) repeat sequence in which glycine is replaced by the D-alanine residue. The hetero-chiral Pro- Ala diad would be erqrected on the basis of stereochemical considerations to adopt a type-II p-tum conformation. Stmctural analyses of small-molecule "Pro- Ala turn models support the formation of the type-II p-mm conformation in solution and the solid state. Polymers based on the (Val-Pro- Ala-Val-Gly) repeat sequence display a thermo-reversible phase transition similar to the corresponding polypeptides derived from the parent (Val-Pro-Gly-Val-Gly) sequence, albeit with a shift of the Tt to approximately 5-10 ° G below the latter due to a slight inaease in hydrophobic character due to the presence of the alanine residue. NMR spectroscopic analyses of the (Val-Pro- Ala-Val-Gly) polymer suggest that the repeat unit retains the p-tum stmcture on the basis of comparison to the corresponding behavior of the (Val-Pro-Gly-Val-Gly) polymer. Stress-strain measurements on cross-linked matrices of the (Val-Pro- Ala-Val-Gly) polymer indicate an elastomeric mechanical response in which the elastic modulus does value in comparison to the (Val-Pro-Gly-Val-Gly) polymer. These smdies of glycine suhstitution support the hypothesis that type-II p-tum formation can he associated with the development of elastomeric behavior with native elastins and elastin-derived polypeptide sequences. Several investigators have proposed that the (Val-Pro-Gly-Val-Gly) pentapeptide represents the minimal viscoelastic unit... 

Furthermore, yet to be computed by any program is the fundamental thermo-mechanical transduction wherein the cross-linked elastic-contractile model proteins contract and perform mechanical work on raising the temperature through their respective inverse temperature transitions. These results first appeared in the literature in 1986 and have repeatedly appeared since that time with different preparations, compositions, and experimental characterizations. Additionally, the set of energies converted by moving the temperature of the inverse temperature transition (as the result of input energies for which the elastic-contractile model protein has been designed to be responsive) have yet to be described by computations routinely used to explain protein structure and function. 

Other thermal analysis techniques such as dilatometry in Sect. 4.1 or thermo-mechanical analysis in Sect. 4.5 can also be used to study the time dependence of T. Especially suited for measurement of the frequency response are dynamic mechanic analyses in Sects. 4.5.4 and 4.5.5, and dielectric thermal analyses in Sect. 4.5.6. Although the different techniques respond to different external excitations, the obtained relaxation times are similar, as shown in Fig. 6.117. Over wider temperature... 

Ding, Z, PumawaU, H., Tang, C., and Zhang, J.L. (2012) Thermo/chemo-responsive shape memory effect in polymers a sketch of working mechanisms, fundamentals and optimization. /. Polym. Res., 19 (9), 1—34. 

The microstructure refinement from the modified thermomechanical treatment is responsible for enhancement of tensile strength and ductility by 18% and 25% respectively. Simultaneously, the stress rupture life as well as ductility is enhanced by virtue of controlled grain size and uniform carbide distribution brought about by the thermo-mechanical treatment. 

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