The Research On Anti-Seismic Performance Of Truss Type Steel Reinforced Concrete Beam Under Vertical Earthquake

In order to study the failure pattern, cracks developments and the seismic performance indexes such as hysteretic curve, skeleton curve, ductility performance, bearing capacity degeneration, energy dissipation capacity, stiffness degradation of truss type steel reinforced concrete beam, this paper conducts an experiment of the truss type steel reinforced concrete beam under vertical low reversed cyclic loading. In this experiment, the effects of different web forms, steel ratio and shera span ratio on seismic performance are considered in. At last, put forward and set up a restoring force model of truss type steel reinforced concrete beam according to the results of experiment. The main results were as follows:(1)The seismic performance of truss type steel reinforced concrete beam is more better than the ordinary reinforced concrete,this beam has a good performance in ductility and energy dissipation,the truss webs and concrete can work together very well and keep stable friction energy dissipation; In the same condition of steel ratio and shera span ratio, the hysteretic curve and skeleton curve of truss type steel reinforced concrete beam which armed with two-way cross webs are more symmetric than the one which just armed with one-way web, the setting of two-way cross webs has larger reverse bearing capacity and displacement ductility coefficient, and favorable for the specimen in symmetrical stress state, thus it can be seen that this beam armed with two-way cross web has excellent plastic deformation and energy dissipation capacity. In the same condition of web forms and shera span ratio, the bearing capacity, ductility and energy dissipation capacity of every specimens raises with the increasing of steel ratio; The seismic performance of shear span ratio components have a certain impact, the ductility and energy dissipation coefficient of specimens which in low shear span ratio reduce in different degree, the seismic energy dissipation capacity are relatively poor, but can still keep good work performance. (2)According to the regression analysis on the experiment data, this paper established the restoring force model of truss type steel reinforced concrete beam, and analyzed on the reasonability of the proposed model, and the result was consistent with the experiment result.