| Carbon fiber reinforced composites(CFRP)are widely used in reinforcement,reinforcement and other fields in civil engineering due to a series of advantages.However,snow icing has a serious impact on the civil engineering construction field and even caused huge economic losses.Therefore,a new anti-icing method becomes particularly important.It is a new development direction to use carbon fibre as a new type of composite material to prevent and remove ice in civil engineering buildings by electric heating.Therefore,this paper studies and manufactures carbon fibre heating laminate with multi-layer structure,and studies its temperature rise characteristics,anti-ice characteristics and mechanical properties.Considering the application environment,repeated use and other factors,the related mechanical properties may decrease and the service life will be shorter.The paper also carried out the cyclic durability test in low temperature environment.The research contents and conclusions are as follows:(1)The structure design of carbon fibre laminate and the material of each structural layer are determined.In order to reduce the influence of some preparation factors on the temperature uniformity,the wire laying die is designed.Three types of heating layers,series S type,parallel type and grid type,are designed for carbon fibre laminates.The resistance stability of the three laminates was verified,and the three laminates with carbon fiber bundle as heating wire had good resistance stability.The temperature-rise characteristics of three kinds of carbon fibre laminates were studied.It was found that with the increase of the same energizing power,the surface average temperature of the three kinds of carbon fibre laminates also increased.After 40 minutes of energizing,the temperature did not rise any more and basically remained stable.Average surface rise temperature of series S-type,grid-type and parallel laminates from large to small.(2)Series S-type carbon fibre laminates have certain anti-icing and de-icing properties.For the anti-icing performance of the laminates,the anti-icing task of 0～-5℃can be completed when the power-on power is 100W/m~2.When the power is 200W/m~2,it can complete the task of anti-icing at 0～-15℃.When the energizing power is 300W/m~2,400W/m~2 and 500W/m~2,the task of anti-icing at 0～-20℃can be completed.The higher the power,the stronger the anti-icing performance.For the deicing performance of the laminates,the laminates undergo three stages:thin ice melting,appearance of melting water film and overall shedding.With the same ice thickness,the higher the power is,the shorter the deicing time of the laminate is.When the power is the same,the ice thickness has little influence on the deicing performance of the laminates.Power on is 500 W/m~2 and ice shedding time is 12.58 min.Power on is 400 W/m~2 and ice shedding time is 16.21 min.Power on is 300W/m~2and ice shedding time is 20.25min.Other smaller power deicing effect is not good.When the ice sheds off as a whole,the average temperature on the surface of the laminates is above 1℃.(3)Carbon fibre laminates prepared by hand-pasting and hot-pressing were compared in tensile strength.The average tensile strength of the hot-pressed laminates was higher than that of the hand-pasted laminates.Hot-pressing increased the average tensile strength of the laminates.In addition,the thickness of the hand-pasted carbon fibre laminates was larger than that of the hot-pressed laminates.Durability tests of hot-pressed laminates with electrical cycles of 100,200,300,400,500,600 and 700 times were carried out at low temperature of -10℃.It was found that within a certain number of cycles,the tensile strength value will increase with the number of cycles increasing,but the increase of tensile strength value becomes smaller and smaller.Until the number of cycles reaches 700,the overall tensile strength value will not increase and decrease.. |
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