Study On The Threshold Of Rubber Trace Removal From Airport Runway By Continuous-nanosecond Laser

In recent years,laser cleaning technology has made great progress and become a very popular way of cleaning.Compared with the traditional chemical cleaning methods,laser cleaning can effectively remove all kinds of surface dirt,and there is no need to use any detergents,only a small amount of dust will be produced in the whole cleaning process,thus greatly reducing the impact on the environment.The matrix will not be damaged during the operation,because this technology has many advantages,so it is widely used in various fields,replacing some traditional cleaning methods.With the continuous progress of laser cleaning technology,it has been successfully applied in industry and other fields.And because it has many unique advantages,its scope of application has become more and more extensive,which makes scientists around the world step up their research on this technology.At present,the main methods used for removing glue are high-pressure water flushing,mechanical brush polishing,and high-temperature combustion.These methods have many drawbacks,such as heavy pollution caused by high-pressure water flushing,low efficiency of mechanical polishing,and high temperature combustion,which can easily damage the road surface and generate dust.As an advanced industrial technology,laser cleaning technology has enormous application value and is developing towards intelligence and high efficiency,bringing enormous potential to industrial development.At present,research methods for laser adhesive removal mostly use a single body laser,and the research method is relatively single.The model establishment,simulation,and experimental testing of continuous nanosecond combination laser debonding are still basically blank.Therefore,conducting threshold research on continuous nanosecond combination laser debonding has important application value and far-reaching practical significance.The research results will provide partial theoretical guidance and experimental reference for the development of laser cleaning,and have important significance for the development of laser cleaning technology.In this paper,the cleaning threshold of CW laser and CW-nanosecond combined laser on the residual glue layer of airport runway is theoretically,simulated and experimentally studied.By cleaning the 100μm glue layer on the surface of concrete,the temperature rise and the change of removal depth of the glue layer irradiated by laser are observed,the best laser cleaning threshold is obtained,and finally the mechanism of combined laser degumming process is clarified.In terms of theoretical research,this article conducts a theoretical analysis of the process of threshold research on continuous nanosecond combination laser removal of airport runway rubber marks.Based on adsorption theory and the formation mechanism of cracking products on the runway,the adsorption mode of the rubber layer is studied.Establish an adsorption mechanical model for the adhesive layer and runway,and calculate through theoretical simulation that the adsorption force between the adhesive layer and the substrate is 3.88×10^-9N.Considering that the temperature rise and ablation process of the target material have a certain coupling relationship with the absorption and propagation of laser energy,independent theoretical modeling is conducted for the three stages of temperature rise,stress,and ablation,namely the temperature rise model,ablation model,and stress vibration model of laser irradiation debonding.In terms of simulation research,the COMSOL Multiphysics finite element analysis software was used to establish the effects of changing the intervention time of the second nanosecond laser on the stress field,temperature field,and removal depth during the continuous laser debonding process with different energy densities and continuous nanosecond laser combinations.Through simulation,it was found that changing the intervention time of nanosecond laser can increase the removal effect.The difference in the way laser energy is received inside and outside the laser irradiation area is the reason for the stress transformation at the laser irradiation edge,and the elastic removal mechanism plays a dominant role at the interface between the adhesive layer and the substrate.In terms of experimental research,orthogonal experiments and single factor experiments were conducted to remove the adhesive layer on the concrete surface.The effects of injecting different continuous laser densities,adjusting the combination laser energy ratio,and changing the nanosecond laser injection time in the combination laser on the temperature field and removal morphology of the adhesive removal process were discussed,respectively.The experimental research results showed that laser energy density was the main factor affecting the removal effect,and adjusting the energy ratio of the combination laser was the main factor,It will improve the cleaning effect.When the nanosecond intervention time changes,it will affect the removal effect of the adhesive layer.This article combines simulation results to ultimately elucidate the threshold mechanism of continuous nanosecond combination laser for removing rubber marks on airport runways.