Damage and failure mechanism of steel arch truss under dynamic loads

Two kinds of failure mechanism, i.e. dynamic instability mainly due to the second-order effect and the strength failure mainly due to the excessive development of plastic deformations under dynamic loads of steel arch truss were studied. Cases of steel arch truss subjected to harmonic actions and earthquake waves were analyzed considering damage cumulative effect and initial geometrical imperfection. The dynamic responses of plastic element ratio, displacement of the key joint, strain energy and plastic displacement of steel arch truss were investigated. The failure mode of structure under various dynamic loads and the corresponding ultimate load were obtained. When the ground motion record was input, the dynamic properties of steel arch truss were analyzed. The results show that when damage cumulative effect is considered, the failure acceleration of steel arch truss structure decreases 22.3%-46.7%; when L/300 initial geometric imperfection is considered, the failure acceleration decreases 2.8%-11.1%. ©, 2015, Central South University of Technology. All right reserved.