A Standalone Vision Sensing System for Pseudodynamic Testing of Tuned Liquid Column Dampers

Experimental investigation of the tuned liquid column damper (TLCD) is a primal factory task prior to its installation at a site and is mainly undertaken by a pseudodynamic test. In this study, a noncontact standalone vision sensing system is developed to replace a series of the conventional sensors installed at the TLCD tested. The fast vision sensing system is based on binary pixel counting of the portion of images steamed in a pseudodynamic test and achieves near real-time measurements of wave height, lateral motion, and control force of the TLCD. The versatile measurements of the system are theoretically and experimentally evaluated through a wide range of lab scale dynamic tests.

Seismic Hybrid Simulation of Stiff Structures: Overview and Current Advances

Advances in the area of structural testing have in recent years led to hybrid simulation, that is, the advanced structural experimental method that encompasses the traditional pseudodynamic testing method and relies on substructuring to offer the advantage of combining the actual experimental testing of selected parts of the structure to the numerical treatment of the rest. The experimental part usually involves simplified test setups and structural elements with few degrees of freedom. Thus, issues of cross-coupling present in testing MDOF structures have not been treated adequately so far. In addition, it has been realized that when it comes to testing very stiff structures, in which the above phenomena are accentuated, further problems arise in relation to the quality of actuator control (accuracy of imposed displacements and stability of the test process). Few studies have focused on these issues, thus necessitating more work in the future. The present study provides an overview of the approaches that have been adopted so far, reports on recent advancements, and raises the points in which more research is needed.

PSEUDODYNAMIC TECHNIQUE TO OBTAIN RELIABLE SHOCK RESPONSE

The use of a pseudodynamic testing method to obtain a response from an impulsive loading may lead to an incorrect test result even though the test setup is properly adjusted and the time step is appropriately chosen based on general considerations. The cause to this problem is analytically explored and a pseudodynamic technique is proposed to overcome this difficulty. The technique is to perform a single small time step immediately upon termination of the applied impulse, while the other time steps can still be conducted by the time step determined from general considerations. The feasibility of this technique is analytically verified and confirmed by a series of pseudodynamic tests for both linear elastic systems and inelastic systems.