Supplemental energy dissipation: state-of-the-art and state-of-the- practice

State of the art of buckling-restrained braces in Asia

Experimental study of steel slit damper for passive energy dissipation

This paper describes a subassemblage seismic test program performed on six buckling-restrained braces (BRBs). Two different brace core segment lengths and two different buckling-restraining mechani...

Seismic testing and performance of buckling- restrained bracing systems

https://ir.nctu.edu.tw:443/bitstream/11536/32367/1/000280018000015.pdf

Subassemblage tests and finite element analyses of sandwiched buckling-restrained braces

The authors developed a buckling-restrained brace that enables increased design freedom at both ends of the core plate and strict quality control while providing stable hysteresis characteristics even under high strains. The buckling-restrained brace can be formed by welding a core plate covered with unbonded material to a pair of mortar-filled channel steels (steel mortar planks) as a restraining part. The use of this approach enables visual confirmation of the status of the mortar filling and also facilitates standardizing structural members and member-by-member quality control. Specimens of a buckling-restrained brace with different steel mortar plank heights are fabricated to adjust the restraining force, along with specimens with different core plate width-to-thickness ratios. The tests were conducted to reveal the hysteretic characteristics of the braces, as well as their cumulative plastic strain energy, elastoplastic properties, and stiffening properties. A performance evaluation formula as well as a buckling-restrained brace design method using the test results is proposed. Copyright © 2006 John Wiley & Sons, Ltd.

Buckling-restrained brace using steel mortar planks; performance evaluation as a hysteretic damper

A damage-controlled structure is defined as a combination of structural systems and energy transformation devices that are integrated in such a way that damage due to a major loading is restricted to a specific set of elements that can be readily repaired. This paper describes a preliminary design methodology for building structures subjected to seismic loading, and presents a comprehensive set of numerical simulations illustrating the response of typical structures designed according to this methodology. The proposed design considers the structure to consist of two independent structural systems that work together to satisfy a design requirement on the deformation. The first system functions as the principal load-carrying mechanism for vertical and lateral service loads, while the second structure’s role is to dissipate and absorb the energy introduced by significant ground shaking. The key design parameters are the elastic stiffness distribution of the primary system, and the damping characteristics of the secondary system. An optimal evaluation of these parameters is presented for a specific choice of material strengths. The data show that the damage control design paradigm generates very good estimates for preliminary design in this case.

Damage-Controlled Structures. I: Preliminary Design Methodology for Seismically Active Regions

This paper first reviews the concept of the damage-controlled structure (DCS) which is a kind of passive damping technology, proposed before the Hyogoken-Nanbu Earthquake in Japan and the Northridge Earthquake in the USA. The philosophy, the necessity and the potential of the damage-controlled structure are stated in the first two sections of this paper. Second, a modified shear-bending beam model and a rational dynamic analysis method of three-dimensional frame for the damage-controlled structure with passive energy dissipation devices are reviewed. Thirdly, a series of dynamic loading test results of modeled damage-controlled steel frame with hysteretic dampers are presented. Finally, a number of actual example building projects which exemplify the current seismic design trend using the passive damping technology in Japan are reviewed.

Passive damping technology for buildings in Japan

This paper proposes a reuse system of building steel structures to reduce environmental burden: specific steps to establish this system are also described. The reuse system mentioned in this paper is an overall business system for realizing a cyclic reuse flow through the processes of design, fabrication, construction, maintenance, demolition and storage. In order for structural members to circulate as reusable members in the distribution system, it is necessary to establish a venous industry; as opposed to an arterial industry which would be responsible for production and supply of newly manufactured members. This venous industry is to facilitate the disposal, recycling and reusing of the products from the arterial industry.

Reuse system of building steel structures

This paper discusses performance evaluation of buckling-restrained braces in damage- controlled structures by numerical analysis using a two dimensional FEM model. Strains at beam-ends in damage-controlled structures are examined. Ductility factors, cumulative ductility factors, and energy absorption ratios of the buckling-restrained braces are investigated from the analytical viewpoints. Tension and compression cyclic loading tests of the buckling-restrained braces are analyzed. Finally, seven types of the buckling-restrained braces are totally evaluated.

Mamoru Iwata

Papers

Buckling-restrained brace using steel mortar planks; performance evaluation as a hysteretic damper

Damage-Controlled Structures. I: Preliminary Design Methodology for Seismically Active Regions

Passive damping technology for buildings in Japan

Reuse system of building steel structures

Performance evaluation of buckling-restrained braces in damage-controlled structures