Building structures must be constructed to dissipate a large amount of seismic energy in order achieve economical earthquake-resistant constructions. In this paper, recent research findings on the effectiveness using steel triangular plates welded as added damping and stiffness (ADAS) device for are presented. Experimental results indicate that properly triangular-plate (TADAS) can sustain number yielding reversals without any or strength degradation. The effects ratio TADAS element bare...

This study investigates the axial load behavior of concrete-filled steel tubular (CFT) columns with width-to-thickness ratios between 40 and 150, proposes an effective stiffening scheme to improve mechanical properties square cross-sectional CFT columns. Seventeen specimens were tested examine effects shapes, ratios, arrangements on ultimate strength, stiffness, ductility Moreover, nonlinear finite element analysis was also conducted investigate stress distribution at strength. Comparing...

The work reconsiders the smooth receding contact between an elastic layer and a half space when two bodies are pressed together. analysis leads to Fredholm integral equation of second kind for auxiliary function that is directly related pressure. An unexpected result homogeneous, finding extent can be viewed as eigenvalue problem. solved numerically any required degree accuracy, pressure computed concentrated uniformly distributed loads in both plane axisymmetric problems. present confirms...

Summary An innovative seismic resisting system consisting of a Pre cast W all with E nd C olumns (or PreWEC) has been developed, and its performance verified using large‐scale cyclic testing. The wall end columns in the PreWEC are anchored individually to foundation unbonded post‐tensioning. A newly designed, low‐cost mild steel connector is used connect horizontally along vertical joint. connectors easily replaceable provide additional hysteretic energy dissipation system. can be...

This paper presents results of an experimental investigation specially detailed ductile perforated steel plate shear walls (SPSWs) designed to accommodate utility passage, and having anchor beams with reduced beam sections connections. Single-story, single-bay SPSW frames are subjected quasi-static cyclic loading up their maximum strength displacement capacity. The tested specimens also had low yield infill panels. Two make allowances for penetration the panel by utilities. first, multiple...

SUMMARY Cyclic loading tests and finite element analyses on six novel all‐steel buckling‐restrained braces (BRBs) are conducted using different patterns to investigate the core plate high‐mode buckling phenomenon. The proposed BRB is composed of a member pair identical restraining members, which restrains by bolted shim spacers. design allows be visually inspected immediately following major earthquake. If necessary, members can conveniently disassembled, damaged replaced. Test results...

SUMMARY Damage to buildings observed in recent earthquakes suggests that many old reinforced concrete structures may be vulnerable the effects of severe earthquakes. One suitable seismic retrofit solution is installation steel braces increase strength and ductility a building. Steel bracings have some compelling advantages such as their comparatively low weight, suitability for prefabrication, possibility openings utilities, access, light. The are typically connected frames fixed structure...

Abstract A series of pseudo‐dynamic tests (PDTs) a full‐scale 3‐story 3‐bay buckling‐restrained braced frame (BRBF) using concrete‐filled tube columns was tested in the Taiwan National Center for Research on Earthquake Engineering networked PDT techniques October 2003. During tests, real‐time experimental responses and video were webcasted to Internet viewers. The input ground motions adopted PDTs chosen from 1999 Chi‐Chi 1989 Loma Prieta earthquakes scaled represent three seismic hazard...

Abstract This paper first presents the force–deformation relationship of a post‐tensioned (PT) steel beam‐to‐column connection constructed with bolted web friction devices (FDs). then describes test program conducted in National Center for Research on Earthquake Engineering, Taiwan, four FDs and full‐scale PT moment subassemblies using FDs. Tests confirm that (1) hysteretic behavior is very stable, (2) coefficient between plate brass shim about 0.34, (3) proposed relationships reasonably...

Abstract This paper is Part II of a two‐part describing full‐scale 3‐story 3‐bay concrete‐filled tube (CFT)/buckling‐restrained braced frame (BRBF) specimen tested using psuedo‐dynamic testing procedures. The first described the design, experiment, and simulation, whereas this focuses on experimental responses BRBs BRB‐to‐gusset connections. evaluates design gusset connections effects added edge stiffeners in improving seismic performance Test results suggest that an effective length factor...

A two-phase experimental program was generated on a full-scale two-story steel plate shear wall with reduced beam section connections and composite floors, to experimentally address the replaceability of infill panels following an earthquake seismic behavior intermediate beam. In Phase I, specimen pseudodynamically tested, subjected three ground motions progressively decreasing intensity. The buckled were replaced by new prior submitting subsequent pseudodynamic test cyclic failure in II. It...

SUMMARY A series of hybrid and cyclic loading tests were conducted on a three‐story single‐bay full‐scale buckling‐restrained braced frame (BRBF) at the Taiwan National Center for Research Earthquake Engineering in 2010. Six braces (BRBs) including two thin BRBs four end‐slotted BRBs, all using welded end connection details, installed specimen. The BRBF was designed to sustain design basis earthquake Los Angeles. In first test, maximum inter‐story drift reached nearly 0.030 rad second story...

SUMMARY The debonding mechanism has a significant effect on the performance of buckling‐restrained brace (BRB). In this paper, method for estimating compression strength adjustment factor any given BRB core strain is presented. Experimental investigations were conducted four BRBs to examine efficiency different materials in reducing difference between cyclic peak and tension. Test results indicate that chloroprene rubber very easy install effective minimizing compressive tensile capacities....

The seismic performance of post-tensioned steel connections for moment-resisting frames was examined experimentally and analytically. Cyclic tests were conducted on three full-scale subassemblies, which had two beams to a concrete-filled tube (CFT) column with high-strength strands provide recentring response. Reduced flange plates (RFPs) welded the bolted beam used increase dissipation energy. Test results indicated that (1) proposed buckling-restrained RFP could dissipate energy in axial...

Abstract Braced frames are one of the most economical and efficient seismic resisting systems yet few full‐scale tests exist. A recent research project, funded by National Science Foundation (NSF), seeks to fill this gap developing high‐resolution data improved braced frame systems. As part study, three full‐scale, two‐story concentrically in multi‐story X‐braced configuration were tested. The experiments examined all levels system performance, up including fracture multiple braces frame....

Summary A thin‐profile buckling‐restrained brace (thin‐BRB) consists of a rectangular steel casing and flat core that is parallel to gusset plate. thin configuration reduces the width restraining member thus saves usable space in buildings. However, deformable debonding layers, which cover plate order mitigate difference between peak tensile compressive axial forces, provide for form high mode buckling waves when thin‐BRB under compression. The wave crests squeeze layers produce outward...

Steel concentrically braced frames designed prior to the implementation of capacity design principles in seismic provisions may exhibit poor inelastic response under excitation. These older, nonductile (NCBFs) used several configurations, with chevron configuration being one most common. The chevron-configured NCBFs is unknown, as relatively large axial and flexural demands are imposed on beam after brace buckling. Current code requirements for special (SCBFs) promote full yielding braces...

Abstract An approximation approach of seismic analysis two‐way asymmetric building systems under bi‐directional ground motions is proposed. The procedures uncoupled modal response history (UMRHA) are extended to buildings simultaneously excited by two horizontal components motion. Constructing the relationships base shears versus roof translations and torque rotation in ADRS format for a building, each pushover curve bifurcates into three curves an inelastic state. A three‐degree‐of‐freedom...

Abstract Six cyclic tests were conducted on three full‐scale subassemblies to investigate the behavior of interior beam‐to‐column post‐tensioned (PT) connections. Strands placed along each side steel beam web, passing through column provide precompression between beams and a column. Top bottom energy‐dissipating (ED) bars, welded beam, used increase moment capacity ED connection. One also had composite concrete slab with discontinuity at centerline eliminate restraint from metal deck,...