Research & Development On The Key Technology Of Roll-forming Of Frame Section Used For New-type Of Construction Formwork

Universal panel formwork which consisting of steel frames and plywood panels is a new-type of construction formwork.It’s one of the future development directions of Chinese construction formwork system.The forming of outer sharp corner and the quality control of high-frequency welding are the key technology to roll form frame sections.These problems are barriers of using the new-type of construction formwork in our country.To develop the frame section used for new-type of construction formwork will improve the Chinese construction formwork system,and utilize the nature resource more reasonable.Cooperating with China Construction Baili Engineering Technology Development Co.Ltd., the research and development on the key technology is completed.The achievements can be described as the following:(1) The forming of outer sharp corner is realized.According to the principle of constant volume,using a special over bending method,some additional metal material is added on both sides of the sharp corner.4 extrusive rolls are used to control the flowing direction of material,and form the required sharp corner.In this way,the problem to roll form the frame section is solved,the forming method is developed for the similar products.(2) The high-frequency welding of the frame section is realized.Using the method of forming-welding,and bending an arc on each side of the coil,a better welding stability and quality is acquired.The influence factor of high-frequency welding quality is analyzed,which provides a theoretic basis for roll design and adjusting.(3) During the research,COPRA FEA RF technology is used to simulate the rollforming progress of frame section.The simulation results validate the main problems appeared in the practice,and reveal the reasons of the problems.It is very helpful to guide the roll design and modification.(4) Using 2 different roll-forming processes,3 frame products with 2 different thickness are developed.The frame products have been exported abroad and used in some construction projects,and good economy benefit is acquired.