應用熔射覆膜技術於摩阻型螺栓接合之滑移係數及潛變行為

Slip Coefficient and Creep Behavior of Bolted Slip-Critical Connections with Thermal Sprayed Coating

張誠(Chang, Cheng)

指導教授 ： 陳誠直

國立交通大學/工學院/土木工程系所/碩士(2019年)

摘要

本研究探討應用熔射覆膜技術於摩阻型接合以提升滑移係數，並確認含塗層摩阻型接合是否符合規範潛變之要求。實驗分為滑移實驗及拉伸潛變實驗兩階段，滑移實驗探討熔射覆膜材料及覆膜厚度對滑移係數的影響；拉伸潛變實驗根據不同滑移係數施加載重，記錄1000小時長期載重下熔射覆膜的潛變所致的滑移量。試體由兩片熔射覆膜連接板搭配僅噴砂母板，以單顆高強度螺栓F10T進行摩阻型接合。滑移實驗結果顯示，使用純鋁及鋁鎂熔射，滑移係數皆可達到0.82至0.94，平均為0.88，為規範噴砂後進行B級塗裝之滑移係數0.50的1.6倍以上。覆膜厚度對滑移係數無顯著影響，但隨著覆膜厚度的增加會造成螺栓預力損失的提高。拉伸潛變實驗結果顯示，熔射覆膜的潛變行為於實驗首100小時對摩阻型接合影響最為顯著，約佔總滑移量80%。純鋁及鋁鎂熔射材料搭配 150 µm覆膜厚度，以滑移係數0.60之設計載重下，通過拉伸潛變實驗並符合規範潛變之要求。本研究以鋁合金熔射覆膜應用於摩阻型接合，可提升滑移係數增加接合強度並應用於工程實務中。

關鍵字

摩阻型接合 ； 潛變 ； 熔射覆膜 ； 滑移係數

並列摘要

This research explore the application of thermal sprayed coating to slip-critical joints to increase the slip coefficient and confirm the slip-critical joints with coating satisfying the creep requirements. The experiment consisted of two sequence tests of slip test and tension creep test. The slip test used to investigate the influence of the coating material and coating thickness on the slip coefficient. The tension creep test was conducted by applied the load calculated based on the slip coefficient, and recorded the slip due to the creep of the coating under a long-term load of 1000 hours. The specimens comprised two splice plates with thermal sprayed coating and a main blasted plate, jointed by a high-strength bolt F10T. The slip test results showed that using pure aluminum or aluminum-magnesium alloy sprayed coating, the slip coefficients could reach 0.82 to 0.94, with an average of 0.88 that was 1.6 times or more than the specified slip coefficient of 0.50 for Class B coating on blast-cleaned steel. The thickness of the coating had no significant effect on the slip coefficient, but as the thickness of the coating increased, the bolt pretension loss increased. The test results of the tension creep test showed that significant creep behavior was observed during the first 100 hours of the test, and the slip during this period was about 80% of the total slip. Specimens with thermal sprayed either pure aluminum or aluminum-magnesium alloy with 150 μm coating thickness, under the design load calculated by a slip coefficient of 0.60, can meet the requirements of the tension creep test. In this research, the application of the thermal sprayed aluminum alloy to the slip-critical joint can increase the slip coefficient and enhance the connection resistance that can be used in engineering practice.

並列關鍵字

slip-critical, ； creep ； thermal sprayed coating ； slip coefficient

參考文獻

American Association of State Highway and Transportation Officials (AASHTO). (2016). LRFD bridge design specification. IL: American Association of State Highway and Transportation Officials, Inc.

American Institute of Steel Construction (AISC). (2016). Specification for structural steel building. Chicago, IL: American Institute of Steel Construction, Inc.

Ampleman, M., Annan, C. D., M., Fafard, M., Lévesque, É. (2015). Long-term slip resistance of metallized faying surfaces used with high strength bolted connections. 4th International Engineering Mechanics and Materials Specialty Conference, Canadian Society for Civil Engineering, At Regina, Volume: Paper # 152.

Ampleman, M., Annan, C. D., Lévesque, É., Fafard, M. (2016). Slip characteristics of combined metallized/galvanized faying surfaces in slip-critical bolted connections. TAC 2016: Efficient Transportation - Managing the Demand - 2016 Conference and Exhibition of the Transportation Association of Canada.

Annan, C.D., Ampleman, M., Fafard, M., Levesque, E. (2016). Long-term creep performance of metalized faying surfaces used with slip-critical bolted connections in steel bridges. World Steel Bridge Symposium.