| China,renowned as a maritime power nation,boasts a lengthy coastline and copious sea resources.However,the marine atmosphere’s high humidity and high chlorine content have resulted in severe corrosion damage to development buildings,such as steel structures and marine platforms,located in coastal areas,causing enormous economic losses.To address this issue,high-performance steel structures,exemplified by stainless steel clad structures,have gained increasing attention as a research and application hotspot in the steel structures field,given their capacity to ensure material corrosion resistance while incorporating structural safety,durability,and cost-effectiveness.Nevertheless,current research primarily concentrates on the material and component level,with scant attention directed towards the application of stainless-clad bimetallic steel(SCS)for connections and nodes.Against this backdrop,this paper focuses on the stainless-clad bimetallic steel plate high-strength bolt connector(SCS-HB),and conducts the following research by means of a combination of experiments and simulations.Calibration of Corrosion Rate in Cyclic Neutral Salt Spray(CNSS)Corrosion Environment in Laboratory: This article designs and produces 30 material standard specimens specifically for corrosion calibration,and conducts a 50-day cyclic salt spray test.The corrosion loss rate is compared with the corrosion test data(Qingdao station)under natural atmospheric environment.Based on the test data,the corrosion model in cyclic salt spray environment is derived.It is found that 1 day under CNSS corrosion environment is equivalent to 1 year under natural corrosion environment.The experimental results clarify the acceleration degree of corrosion in CNSS environment,and also provide a reliable time basis for comparing the results of accelerated corrosion test with those under natural atmospheric conditions in the future.In terms of the analysis of the shear performance of SCS-HB,this article conducted a total of 4 groups(36 in total)of monotonic tensile tests on stainless-clad bimetallic steel plate ordinary high-strength bolt and stainless-clad bimetallic steel plate stainless steel highstrength bolt specimens under different corrosion durations,including the determination of the anti-slip coefficient,bolt pre-tightening force,and observation of the change in the ultimate bearing capacity of the connections.Rather than using the overall corrosion degree as the judging criterion,the individual corrosion degrees of the plate and bolt were considered to gain an in-depth understanding of the influence of their different degrees of corrosion on the connection performance.The experimental results revealed that with the increase of corrosion duration,the stainless-clad bimetallic steel plate and stainless steel bolts exhibited good corrosion resistance,while the corrosion degree of ordinary high strength bolts increased with time.Additionally,both stainless steel bolts and ordinary high strength bolts showed a decreasing trend in pre-tightening force,with the pre-tightening force of stainless steel bolts decreasing significantly less than that of ordinary high strength bolts.After experiencing 100 days of corrosion,the pre-tightening force of ordinary high strength bolts decreased by about 57%,while that of stainless steel bolts only decreased by about 24%.The anti-slip coefficient of ordinary high strength bolt connections showed a linear decrease trend,decreasing by about 13% after 100 days.However,for the connections with stainless steel bolts,the anti-slip coefficient showed no significant influence by different corrosion durations.In the context of finite element analysis of stainless steel clad steel plate-high strength bolt connections,this study modeled the connections using ABAQUS finite element software and validated the accuracy of the model by comparing it with experimental results presented in this paper.Furthermore,a performance degradation model of stainless steel clad steel plate-high strength bolt connections under a corrosive environment was established based on the relationship between the bolt corrosion weight loss rate and the preload force reduction.The experimental data were improved by varying the corrosion period,providing a theoretical basis for the application of stainless steel clad steel platehigh strength bolt connections in practical engineering and data support for the safety assessment of these connections after corrosion. |
