Strut model and seismic performance of infilled frame structures considering the influence of constructional columns

It is generally accepted that infilled walls play an important role in the structural response to seismic excitation, and most studies have ignored the influence of constructional columns, which is a potential hazard in the seismic design of structures. Numerical simulation is an important tool for seismic design, but complex and sophisticated finite element models are often not suitable for structural design, so a reliable and efficient numerical model is required. The equivalent strut model is the most widely used model for infilled frames due to its simplicity and efficiency. This paper proposes a new single-strut macro-model and an empirical formula for strut width for modeling frames with constructional columns and infilled walls. The model is developed based on previous experimental observations. The reliability of the model is verified by setting up equivalent struts to account for the potential failure of the constructional column infilled wall, which is based on the calibration of the test data. Finally, the seismic response of a multi-story multi-span monolithic frame model is investigated, the influence of constructional columns and infilled walls on the seismic performance of the frame is also explained and design recommendations are made for the natural period discount factor for infilled walls in the Chinese code.