A novel stochastic linearization technique for structures with nonlinear fluid viscous dampers including soil-structure interaction

The nonlinear force-velocity behavior of fluid viscous dampers (FVDs) complicates the design of structures fitted with such elements. Soil-structure interaction (SSI) changes the response of the structure and thus the FVD force, making the design even more complex. This study proposes a novel stochastic linearization technique (SLT) to analyze structures with nonlinear FVDs by considering SSI and optimum non-Gaussian probability density functions (PDFs). To achieve this, single-degree of freedom (SDOF) systems on both firm and soft soil types were first analyzed. The maximum computational error of the standard deviation of displacement and velocity for the studied systems was 1.8% using the proposed SLT, compared to errors of up to 7.2% using Gaussian PDFs. A comprehensive parametric study was then conducted for other non-dimensional SDOF systems with SSI, as well as for a case study multi-degree of freedom structure. In general, the results indicate that the proposed SLT considerably reduced the computational errors of the predicted responses. This study contributes towards developing more efficient methods to analyze and design structures fitted with nonlinear FVDs including SSI effects, which is necessary for the wider adoption of FVDs in construction.