Study On H-beam Straightening Mechanism And Dynamic FEM Simulation

Because H-beam has many advantages such as economical section, lightweight, goodbearing capacity, lower fabrication cost and easily rivet, it is applied widely in industry and civilsteel construction and has a capacious application perspective. But H-beam has taller flangesand a thinner web and its roller straightening is a typical elastic-plastic statically indeterminatestructure. So it is difficult to study straightening mechanism of H-beam in theory and practice.In this paper, straightening mechanism of H-beam is studied in detail according to elastic-plastictheory, FEM, simulation and test. The main contents and achievements are as follows:1. Bending deflection on H-beam roller straightening which is the key technical parameteris studied in detail based on elastic-plastic theory. Universal formulae on bending deflection ofone straightening element are deduced. The relations among bending moments, straighteningforces and bending deflections of H-beam nine-roller straightening are deduced.2. Correctness of theoretical analysis is validated by FEM. By static simulating oneelement and nine-roller straightening the relation of bending deflection and straightening forceof rollers is studied. And the variety rule of stress and strain is studied in detail.3. H-beam straightening mechanism including hereditary characteristic is studiedtheoretically. The variety rule of residual deflection and residual stress is studied. The formulaeof residual deflection and residual stress on H-beam roller straightening are deduced. Thevariety of bending moment and elastic area ratio including hereditary characteristic is illustratedand modified method is brought forward.4. Three-dimensional elastic-plastic FEM model is set up. H-beam straightening processincluding entering, straightening steadily and leaving is simulated dynamically. The principle ofdeflection and straightening force and stress is researched on perfect or hardening materials H-beam whose relative original curvature equals zero or not. The results of simulation show thatthe theoretical analysis above is correct.5. Geometric shape of H-beam before and after straightening is tested. Bendingmathematic model of typical H-beam is a superpose of sin and multinomial curve. Geometricshape and energetic parameters of H-beam are tested for different bending deflection. Theresults of test show that theoretical and simulation analysis is correct.