- Author
- Saunders, S. C. | Jensen, M. A. | Martin, J. W.
- Title
- Study of Meteorological Processes Important in the Degradation of Materials Through Surface Temperature.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Report
- NIST TN 1275, April 1990, 45 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- diurnal cycle | energy-balance equation | environmental factor | Fourier analysis | meteorological data | panel temperature | time series analysis | forecasting
- Abstract
- One of the greatest impediments in forecasting the service life of a material exposed outdoors is the uncontrolled and non-predictable nature of the ambient factors comprising its environment. This contributes to the difficulty of establishing the cause-and-effect relationship between these factors and the rate of material degradation. To surmount these difficulties it is necessary to characterize quantitatively each of the factors comprising the exposure environment which are thought to be important in the material's degradation. The selection and quantification of these factors must accommodate not only the periodicity of the diurnal cycle but its statistical fluctuation. The objective of this research is to develop a general mathermatical model, through Fourier analysis, characterizing the diurnal variation in the primary factor, material temperature. This factor is felt to be important in the degradation of a wide range of materials and protective systems, including coated steel panels. The steps taken and problems encountered in developing such a model are outlined. It is concluded that the simulated data generated from this model display virtually the same stochastic behavior as does the real data and that, if appropriate metorological records are available, it will be possible to characterize and reproduce the statistical behavior for any locality, season and panel orientation.