Evaluation And Technique Investigation Of Steel-Concret Simple-Supported Beam-Bridge Under Attached Load

Traffic is economics lifeline of society, bridge is unblocked throat of traffic, Its smooth will restrict social development of economy. So it is essential to ensure the functionality of the bridge, especially the security. This needs to carry on security measuring and monitor to the bridge frequently, so as to ensure the normal use of the bridge. Traditional quiet load methods of bridge test need the heavy working range, long time to load, and usually breaking down the traffic. So there is the realistic and importance meaning to study a kind of simple, convenient, swift test method about bridge damage.To solve this question, finite element software ANSYS is utilized to analysis the mode of steel concrete beam and bridge in this text. Natural frequency is a parameter easiest to obtain in modal parameters, and relatively high discern precision, but it is very unsensitive to damage, so this text put forward the method of attached load, expand the change value of frequency through adding the load. At first, utilize finite element software ANSYS go on model analysis to simple-supported steel concrete beams and bridges composed of roof beams to daily armored of section (T beam, hollow board). Under the different attached load, rigidity, stepping the foot-path and sectional form, we can draw a series of vibration frequency value, and derive out the theory relational expressions about frequency and relevant factors. It offers succinct way for utilizing the attached load method through frequency application of rigidity. Then, a simple-supported steel concrete beam model is study on the condition of static attached load and dynastic attached load. Through the test, we draw a series of value about stress, deflection and natural frequency correspond the load. Utilize theory formula of deflection and rigidity, frequency and rigidity to draw the static rigidity and dynastic rigidity in different load. The consistency of the final result indicates that it is feasibility that the dynastic test replaces the static tests under attached load. Finally, combine the instance bridge measure, through analysis of the result of static load and dynastic load, it further proved the method of attached load is feasibility and superiority.