Deformation Of Thermal Insulatiion Material Under The Action Of Temperature

Exterior insulation technique has become the mainstream for convenientconstruction, space savings as well as protection for wall. From1997, building energyefficiency began to be enforced in China and meanwhile energy saving standards forbuildings changed from30%to50%gradually. With the implementation of a newdesign standard for energy efficiency of residential buildings in some areas, buildingenergy-saving rate in China will reach the advanced level of developed countries. Inthis paper, elastic modulus, Poisson ratio as well as linear thermal expansioncoefficient of insulation boards, including EPS and XPS, were measured to providebasic physical and mechanical parameters for finite element analysis. The temperaturedistribution within the wall was discussed using numerical methods for buildingexterior insulation wall whose one side was in different atmospheric temperature withanother side toward to indoor. Besides, the effect of air layer, type of insulation boardand wall materials on the interior temperature field distribution for the exteriorinsulation wall including was also studied. Moreover, two typical kinds of exteriorinsulation wall (made up by insulation board coupled with concrete and aeratedconcrete, respectively) were selected to study the temperature distribution underdifferent temperatures which provided boundary conditions for temperatureformation.Strain distribution along thickness direction of internal strain and temperaturedistribution along the wall thickness for different insulation materials were obtainedby finite element simulation method for different insulating materials insulation boardunder different temperatures In real project, thermal deformation of the plate willresult in the interface bond stress between insulation board and substrate and thereforeinsulation damage due to bond failure is a common phenomenon.. In order to solvethe above problem, we build ANSYS finite element model and restrict heatingboundary condition to obtain internal temperature field of exterior insulation wall.Furthermore, finite element structural analysis of boundary conditions are defined inthe model with thermal analysis of temperature fields as bulk loads applied to thestructure model to obtain stress field. Maximum stress at the interface withtemperature curves is gained by the interfacial data from the infinite element analysis.By changing the boundary condition on the structure of the model, the relationbetween temperature stress and bond area can be calculated simulating differentbonding areas between the insulation boards and wall.At last, temperature field distribution and strain distribution of two kinds ofinsulation board were measured through tests under different temperature conditionswhich were compared with the simulation values and the reasons for the differences were also analyzed.