STATIC AND DYNAMIC ANALYSIS OF A TRUSS BRIDGE

U diplomskom radu provedena je numerička statička i dinamička analiza rešetkastog mosta duljine 30 m, širine 6 m i visine 5 m, koji je oslonjen na dva oslonca. Modeliranje rešetke mosta je izvedeno korištenjem standardnih grednih profila izrađenih od konstrukcijskog čelika. S ciljem postizanja povjerenja u numerički model rešetke mosta provedena je verifikacija primjenjenih grednih konačnih elementa na primjeru ravninskog rešetkastog nosača. Za izradu 3D modela mosta korišten je računalni program Space Claim, koji je dio paketa Ansys 2019 R2. Za samu numeričku analizu korišten je Ansys Mechanical program za analizu metodom konačnih elemenata. Za statičku analizu mosta korišteno je opterećenje uslijed vlastite težine mosta i dodatno opterećenje betonske ploče mosta u iznosu 500 kg/m2. Nakon statičke analize provedena je tranzijentna analiza mosta, kojom je simulirano gibanje vozila različitih masa i različitih brzina. Na temelju tranzijentne analize određen je dinamički faktor kao omjer progiba uslijed tranzijentnog i statičkog opterećenja. Na kraju je provedena modalna analiza kojom su utvrđene vlastite frekvencije i forme vibriranja mosta.In this thesis, a numerical static and dynamic analysis of a truss bridge 30 m long, 6 m wide and 5 m high, which is supported by two supports, was performed. Modeling of the bridge truss was performed using standard beam profiles made of structural steel. In order to gain confidence in the numerical model of the bridge truss, the verification of the applied beam finite elements was performed on the example of a planar truss. The computer program Space Claim, which is part of the Ansys 2019 R2 package, was used to create a 3D model of the bridge. The Ansys Mechanical finite element analysis program was used for the numerical analysis itself. For static analysis of the bridge, the load due to the own weight of the bridge and the additional load of the concrete slab of the bridge in the amount of 500 kg/m2 were used. After the static analysis, a transient analysis of the bridge was performed, which simulated the movement of vehicles of different masses and different speeds. Based on the transient analysis, the dynamic factor was determined as the ratio of the deformation due to the transient and static load. Finally, a modal analysis was performed to determine the natural frequencies and vibration modes of the bridge