Development of DDBD for steel MRFs using inelastic response-based seismic lateral force distribution

This paper presents a proposed optimum tire force distribution method in order to optimize tire usage and find out how the tires should share longitudinal and lateral forces to achieve a target vehicle response under the assumption that all four wheels can be independently steered, driven, and braked. The inputs to the optimization process are the driver’s commands (steering wheel angle, accelerator pedal pressure, and foot brake pressure), while the outputs are lateral and longitudinal forces on all four wheels. Lateral and longitudinal tire forces cannot be chosen arbitrarily, they have to satisfy certain specified equality constraints. The equality constraints are related to the required total longitudinal force, total lateral force, and total yaw moment. The total lateral force and total moment required are introduced using the model responses of side-slip angle and yaw rate while the total longitudinal force is computed according to driver’s command (traction or braking). A computer simulation of a closed-loop driver-vehicle system subjected to evasive lane change with braking is used to prove the significant effects of the proposed optimal tire force distribution method on improving the limit handling performance. The robustness of the vehicle motion with the proposed control against the coefficient of friction variation as well as the effect of steering wheel angle amplitude is discussed.

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SEISMIC LATERAL FORCE DISTRIBUTION FOR DUCTILITY-BASED DESIGN OF STEEL PLATE SHEAR WALLS

Journal of Earthquake and Tsunami ◽

10.1142/s1793431112500042 ◽

2012 ◽

Vol 06 (01) ◽

pp. 1250004 ◽

Cited By ~ 4

Author(s):

SWAPNIL B. KHARMALE ◽

SIDDHARTHA GHOSH

Keyword(s):

Steel Plate ◽

Shear Walls ◽

Shear Wall ◽

Lateral Force ◽

Performance Based Design ◽

Force Distribution ◽

Steel Plate Shear Walls ◽

Steel Plate Shear Wall ◽

Design Requirements ◽

Ductility Ratio

The thin unstiffened steel plate shear wall (SPSW) system has now emerged as a promising lateral load resisting system. Considering performance-based design requirements, a ductility-based design was recently proposed for SPSW systems. It was felt that a detailed and closer look into the aspect of seismic lateral force distribution was necessary in this method. An investigation toward finding a suitable lateral force distribution for ductility-based design of SPSW is presented in this paper. The investigation is based on trial designs for a variety of scenarios where five common lateral force distributions are considered. The effectiveness of an assumed trial distribution is measured primarily on the basis of how closely the design achieves the target ductility ratio, which is measured in terms of the roof displacement. All trial distributions are found to be almost equally effective. Therefore, the use of any commonly adopted lateral force distribution is recommended for plastic design of SPSW systems.

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