In The Process Of The Pipe Pressure Straightening On-line Detection And Straightening Mathematics Model Is Established In This Paper

Press straightening is a technology which erases or reduces bend of longsteel parts. It is simple, flexible and economical steel pipes which are importantproducts in metallurgical industry are widely used in ships, bridges, constructionindustries and other fields. When they are used, they will be out of shade becauseof the force and other reasons. When the deformation of the steel pipe exceeds acertain degree, it will not be able to be used again. It can be restored through thepressure straightening at this moment, and then it can reach the conditions ofusing. Straightening prolongs the service life of the steel pipe and createsremarkable economic benefit.Steps of the traditional pressure straightening are:(1)Place the steel pipein the pressure straightening machine, flip the steel pipe by experiences, thenstraighten it by straightening machine, make sure that the head can fall at itsmaximum deflection;(2)When the straightening machine straightens the steelpipe，depress loading or rolling reduction or is calculated according toexperiences, so normally steel pipes can’t be straightened once, it requires manytimes until the steel pipe is straight.The above steps work according to the workers’ experiences, low efficiency,and the accuracy of the straightening is not enough, this article is researched on tosolve the defeats above the steps. at the first step, provide a precise positioningmethod to measure the steel pipe, and use the least squares method to establish amathematical model of measuring curve of the bending steel pipe, reduce theerror caused by turning the steel pipe by hands;at the second step, when the pipe’souter diameter, inner diameter, and material quality are ensured, according to theinitial curvature,establish the mathematic model of depress loading and the initialbending deformation or establish the mathematical model of rolling reduction andthe initial bending deformation. Finally, by finite element analysis software,wecompare the loaded bending curvature value with the initial bending curvaturevalue of on-line detection, their curvature values are especially closed to each other.It is proved that load calculated from the straightening mathematical modelcan straighten the bent steel pipe.