A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Untersuchungen zum thermo- und hydromechanischen Verhalten transparent gedämmter Wände
Within a transparently insulated wall occur in dependence of the thickness of the wall and the mass-density temperatures up to 80 deg C. The instationary temperature fields induce stresses even without constraints. If a wall is partially tiled with transparent insulation especially the regions within the wall cross-section behind the opaque-transparent insulation boundary are of interest. In this case two-dimensional temperature- and stress calculations are necessary. As well as temperature loads, variations of the moisture content within a building material induce expansion or shrinking and therefore stresses. This behaviour is amplified due to the high material temperatures occurring under the influence of the transparent insulation. The aim of the present paper is to investigate the stress and strain states within a transparently insulated wall due to temperature and moisture variations. For this reason a test-wall from sand-lime-stone was built up into a conditioned chamber. The south-directed wall-surface with an area of 4 m2 was partially transparently insulated with the 'Sto Therm Solar'-system on an area of 1,2 m2. This surface was exposed to natural climate whereas the other wall surface was directed into the chamber with a constant temperature of 23 deg C. The initial moisture content of the sand-lime-bricks was 18 volume-%. To avoid additional stresses, the wall was built up on a gliding baseplate and without constraints along the edges. During the drying-up of the wall strains, temperatures, heat fluxes and moisture contents were measured. After all the temperature and humidity fields within the wall cross-section were calculated with the numerical program 'DIM3.l'. A good coincidence between the measured and calculated moisture content was obtained. On the basis of these results the strain and stress analysis was performed using the FE-program 'Abaqus'. Because of the ideal assumptions this computation yields inner surface strain and bending results of about double the values of the measurements. On a typical sunny cloudless day the maximal bending of the wall occur at 2 p.m. In the same case the maximal tensile stress occur at 6 p.m. within the absorber surface layers due to the superposition of thermally and hygrically caused tensile stresses. It is possible to obtain qualitative information about the extreme states of strain and bending as well as about the maximum tensile stresses. Therefore the used calculation methods represent a good tool for predicting harmful stress states within a transparently insulated wall.
Untersuchungen zum thermo- und hydromechanischen Verhalten transparent gedämmter Wände
Within a transparently insulated wall occur in dependence of the thickness of the wall and the mass-density temperatures up to 80 deg C. The instationary temperature fields induce stresses even without constraints. If a wall is partially tiled with transparent insulation especially the regions within the wall cross-section behind the opaque-transparent insulation boundary are of interest. In this case two-dimensional temperature- and stress calculations are necessary. As well as temperature loads, variations of the moisture content within a building material induce expansion or shrinking and therefore stresses. This behaviour is amplified due to the high material temperatures occurring under the influence of the transparent insulation. The aim of the present paper is to investigate the stress and strain states within a transparently insulated wall due to temperature and moisture variations. For this reason a test-wall from sand-lime-stone was built up into a conditioned chamber. The south-directed wall-surface with an area of 4 m2 was partially transparently insulated with the 'Sto Therm Solar'-system on an area of 1,2 m2. This surface was exposed to natural climate whereas the other wall surface was directed into the chamber with a constant temperature of 23 deg C. The initial moisture content of the sand-lime-bricks was 18 volume-%. To avoid additional stresses, the wall was built up on a gliding baseplate and without constraints along the edges. During the drying-up of the wall strains, temperatures, heat fluxes and moisture contents were measured. After all the temperature and humidity fields within the wall cross-section were calculated with the numerical program 'DIM3.l'. A good coincidence between the measured and calculated moisture content was obtained. On the basis of these results the strain and stress analysis was performed using the FE-program 'Abaqus'. Because of the ideal assumptions this computation yields inner surface strain and bending results of about double the values of the measurements. On a typical sunny cloudless day the maximal bending of the wall occur at 2 p.m. In the same case the maximal tensile stress occur at 6 p.m. within the absorber surface layers due to the superposition of thermally and hygrically caused tensile stresses. It is possible to obtain qualitative information about the extreme states of strain and bending as well as about the maximum tensile stresses. Therefore the used calculation methods represent a good tool for predicting harmful stress states within a transparently insulated wall.
Untersuchungen zum thermo- und hydromechanischen Verhalten transparent gedämmter Wände
Fischer, U. (author)
2000
6 Seiten, 6 Bilder, 6 Quellen
Conference paper
German
Gemauerte und vorgefertigte Wände : Untersuchungen
| UB Braunschweig | 1962
Gemauerte und vorgefertigte Wände : Untersuchungen
| TIBKAT | 1962
| UB Braunschweig | 2019
| UB Braunschweig | 2015