| In Inner Mongolia region,the special natural environments such as temperature and humidity fluctuations,strong ultraviolet and blown sand affect the durability of building glass curtain walls,solar panels and train windows,and seriously influence their service life.This study carried out the weathering test of the tempered glass on the basis of the statistical analysis of the temperature,humidity and UV environment in this area,and used EDS to analyze the changes in the content of the glass surface products compared with the matrix chemical elements after aging,and determined the type of the products.The law of erosion rate of tempered glass before and after environmental aging with erosion parameters was studied by means of airflow sand injection method.The erosion process and damage mechanism were analyzed by the scanning electron microscope and laser scanning microscope damage morphologies.The contribution degree of each influence factor to the erosion rate is studied by Taguchi method.A two-dimensional model of the erosion specimen was established,and the erosion rate of tempered glass under different erosion parameters was simulated by Fluent software,and the results were compared with the experimental results.This study is subject to the National Natural Science Foundation of China(Study on the mechanical behavior and damage mechanism of the windshield glass under the special environment of the region)(No.11662012),(Study on erosion mechanical behavior and damage evaluation of steel structure coating under wind sand environment)(No.11162011),(Study on damage mechanism of sand erosion of pavement concrete in Western salty area under cold environment)(No.51468049),the specific contents are as follows:1?Through testing the basic optical and mechanical properties of tempered glass,transmittance,hardness and modulus of elasticity of tempered glass were obtained.The characteristics of temperature,humidity,ultraviolet and wind sand environment in Inner Mongolia area were analyzed,and the test conditions were designed under four different working conditions.2?The environmental aging test of the tempered glass under the temperature and humidity cycle and the ultraviolet rain condition were carried out.The test results show that:(1)The transmittance reduction of tempered glass decreases with the increase of temperature and humidity cycle times.And material is formed on the surface of the glass.White spots are scattered from the SEM diagram on the surface of glass,and the substance is mainly sodium salt by EDS analysis.(2)The transmittance reduction of the tempered glass decreases with the increase of simulated UV rain years.The SEM diagram shows there are white substances and locally cracks on the toughened glass surface after experimental simulation of ultraviolet rain for 3 years.The damaged surface is cleaned by deionized water and there are tiny corrosion pits.This is due to the ion exchange on the surface of the glass and the destruction of the glass structure by the alkali solution formed in the later period,which jointly promotes the damage of the glass surface.3?The sandstorm erosion test was performed on tempered glass subjected to temperature and humidity fluctuations and ultraviolet rain through a simulated wind erosion environment test system,and erosion data was analyzed.Combined with scanning electron microscopy(SEM)and laser scanning confocal microscope(LSCM)observation of surface morphology of erosion,erosion damage mechanism before and after aging was analyzed.The results showed that:(1)Temperature and humidity cycles and UV rain have a little influence on glass surface,and the erosion rate increases approximately linearly with erosion angle,and increases exponentially with erosion velocity,and decreases with the sand flow rate in the experimentally sand flow range.(2)The erosion rate of tempered glass increases with the number of cycles of temperature and humidity alternating,and decreases with simulated ultraviolet rain years firstly,then increases,but the overall change is small.(3)Under the conditions of simulated ultraviolet rain,the erosion rate increases with the erosion time,and there are two stages of rising and steady erosion.At low erosion angle,erosion rate at different ultraviolet ages successively went to steady state at 30~40min.When high angle erosion occurs,it will enter steady state successively at 20~30 min.(4)The results of the erosion test on the irradiated and unlighted glass show that the erosion rates of the two are similar with the change of erosion parameters,so the effect of ultraviolet on the erosion rate of the glass under the temperature and humidity environment may not be considered.(5)At low erosion angle,the glass damage is mainly dominated by cutting.In the SEM image,there is a downwind groove.After the environmental aging,the erosion groove is deep and long.During high-angle erosion,irregular fracture pits appear in the damaged topography of the glass,and a large number of cracks appear at the bottom and around the pit.After aging,the glass erosion pits are comminuted and cracks are wide and long.From the perspective of laser scanning confocal microscope(LSCM),the erosion pit parameters of the glass after the temperature and humidity alternating cycle are larger than those of the uncirculated glass.The erosive damage surface changes from ellipse to circular shape with the increase of erosion angle.4?Experimental study on wind sand erosion test under temperature and humidity fluctuations and ultraviolet rain was carried out through the application of Taguchi orthogonal test method.The results show that erosion angle is the most important factor on the erosion rate of tempered glass with the largest contribution rate,followed with erosion speed.And sand flow rate,cycle number and ultraviolet age(test range)have the least influence on erosion rate.5?The two-dimensional model of the tempered glass is simulated the wind sand erosion environment through the Fluent software,and we obtain erosion maps,flow velocity contour,sand erosion velocity and trajectory map under different impact angles.The erosion process of high-speed airflow to the specimen is analyzed combining with the erosion profile of the laser confocal microscope(LSCM),and the simulation erosion rate and the test result are compared and analyzed.This simulation results provide a basis for the protection of materials. |
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