engleski

Model quality assessment for RC frames with URM infill walls subjected to horizontal cyclic loading

Any engineering judgement of the functionality, safety, reliability and robustness of structures requires forecasting models, which in general have (often unknown) limits of their applicability and a somehow uncertain quality concerning their evidence and predicted quantities. In particular, this is true in cases of dynamic action reaching extreme intensity levels to cause non-linear response. The paper focusses on RC frame with unreinforced masonry (URM) infills. Since the turn of the millennium, a number of distinct experimental studies led to a number of numerical macromodels with different complexity able to represent the behavior of the investigated primary and secondary structural systems addressing the in-plane (IP) response of the RC frame with URM infill walls. Concentrated plasticity models like lumped plastic hinges and fiber-based modeling approaches are often used to simulate the behavior of the RC frame elements. Besides, the concept of equivalent diagonal struts is usually utilized to represent the effect of full URM infill walls. The nonlinear cyclic behavior of the numerical model is described by means of a strength envelope curve linked with a distinct hysteresis law. Several welldocumented experimental tests are chosen for the evaluation of the simulation results obtained by utilizing a set of different macromodels. They represent the proposed modeling techniques of RC frame elements and URM infill walls as well as different hysteretic models. By comparing the experimental and numerical results the model quality has been assessed with respect to deformation and stiffness properties as well as application of error measures. A tested four-story RC frame structure with URM infill walls, considering the IP response only, will be used to re-assess the failure mechanism of the structure through the use of the proposed simplified numerical model. Finally, a simple and reliable model can be recommended to be further used.

Model quality ; RC frames ; URM infill walls ; macromodelling

nije evidentirano