Research On The Natural Vibration Characteristics Of Curved Composite Beam With Single-box Double-cell Section And Corrugated Steel Webs

This article relies on the National Natural Science Foundation of China’s "Corrugated Steel Web Prestressed Concrete Curved Composite Beams under Torsion Mechanism and Calculation Theory Study"(51778377).The characteristics are analyzed by a combination of theoretical derivation,experimental model measurement and finite element software analysis.The main research contents and conclusions are as follows:(1)Combining the dynamic principle with the energy variation principle and the Hamilton principle,ignoring the bending effect of the corrugated steel web,and considering the shear strain energy of the corrugated steel web and the shear lag effect of the upper and lower flange plates,The bending and torsion coupling effects of curved beams are mainly considered to formulate and study the vertical bending vibration of simply supported beams with corrugated steel webs and composite curved beams.The formula for calculating the bending vibration frequency of curved simply supported box beams is obtained.solution.The results obtained from the derived formula are in good agreement with the experimental measured values and the finite element analysis values,which verifies the correctness of the calculation formula.(2)Design and manufacture corrugated steel web curve combination test beams.Use DASP dynamic signal test analysis system to conduct indoor test on model test beams,and measure the bending vibration frequency,torsional vibration frequency and mode shape of the test beam.The finite element model of the model beam was established using ANSYS software,and the numerical analysis results were compared with the measured results.The two agree well.The comparison test results show that as the span ratio of the test beam increases,the fundamental frequency of the first-order vertical bending mode becomes smaller;as the number of diaphragms increases,the torsional performance of the test beam is improved,but compared to The four diaphragms and seven diaphragms did not significantly improve the torsion of the beam.(3)The parameter analysis was performed using a corrected finite element model.The results show that the vertical vibration frequency of curved beams increases with the thickness of the corrugated steel web and the number of diaphragms.Decreased;transverse bending vibration increases with increasing plate thickness,number of diaphragms,and width-to-span ratio,and decreases with increasing span ratio;torsional vibration frequency increases with span ratio,plate thickness,and number of diaphragms Larger and larger,and smaller as the width-to-span ratio increases.The comparison of straight beam results shows that the difference between the vertical second-order vertical vibration frequency of the straight beam and the curved beam does not change with the increase of the plate thickness,and the frequency difference of lateral bending vibration and torsional vibration increases,but the rate of change slows down;The frequency difference between the first fourth-order frequency of the straight beam and the curved beam does not change after the establishment of.The torsional vibration frequency difference is reduced.