Cyclic tests of four two‐story narrow steel plate shear walls. Part 2: experimental results and design implications

Abstract

This paper is the second part of a two-part paper presenting the cyclic tests of four two-story narrow steel plate shear walls (SPSWs). The first paper introduces the analytical studies and the specimen designs. This paper describes the test results. Some design implications including the capacity design for the first story column and the width-to-thickness ratio check for the beam web are discussed based on key observations from the tests. Test results confirm that the simplified strip model can accurately predict the inelastic responses of the specimens. Test results also confirm that the proposed capacity design method is effective in ensuring the plastic hinge formation at the bottom end of the first story column for SPSW with or without restrainers. Test results also show that the horizontal restrainers are effective in reducing the member forces in the boundary beam and column elements. Comparing the test results of the typical SPSW with those of the restrained SPSW (R-SPSW) specimens, it is found that the R-SPSW possesses an improved cyclic performance and reduced material weight. Analytical results predict the compressed column moments at the onset of the column plastic hinge formation well. The analytical hysteretic energy distribution in the first story column agrees very well with the observed inelastic actions developed in the four specimens. The detailed frame response analyses and the test results confirm that the assumptions made in developing the proposed column capacity design method are reasonable.KEY WORDS: steel plate shear wall (SPSW); restrained steel plate shear wall (R-SPSW); capacity design; narrow steel plate shear wall Figure 1. Details of the specimens.beam-to-column joint for both the middle and the top beams. Thus, the unbraced length of the columns was equal to the story height. A reference column was erected to measure the lateral displacement of the specimens at various elevations ( Figure 2). Positive values of force or displacement indicated pushing or movement toward the east direction. The cyclic displacements were imposed according to the loading history shown in Figure 3, starting from small roof drift and increasing up to 5% radian. The north actuator was displacement controlled while the south one was force-slaved.

Sub-structural pseudo-dynamic performance of two full-scale two-story steel plate shear walls

“…34 shows that the analytical response computed using the strip model and the EB model are almost equivalent. Similar analytical results were also presented in other research [16]. This strongly suggests that the EB model can be effectively used for the preliminary design and global seismic response analysis of properly proportioned SPSW buildings.…”

“…In order to ensure that the tension field action can be developed, the capacity design method was applied to check the adequacy of the boundary elements. The capacity design of the boundary elements has been proposed by other researchers [1,16]. A simplified but conservative approach has been adopted in this study, as given below.…”

“…Additionally, if the detail of the restrainers processed the proper design, the restrainers can effectively reduce the force demands in beams and columns. The smaller member size can be chosen as boundary elements [16]. During the two phases of testing, all the key analytical predictions and experimental responses were broadcasted from a website (http://exp.ncree.org/spsw).…”

Cyclic tests of steel plate shear walls using box‐shape vertical boundary elements with or without infill concrete

“…As shown in Figure 16-right, the experimental curvatures are measured by six tilt-meters (T1-T6) installed over the bottom half of each 1F VBE. Thus, before the in-span plastic zone developed in a bottom VBE, the VBE should have suffered some plastic rotations at its bottom end during the previous cycles [19]. For specimens NSB, NCB, and WCB, the VBE segments having the maximum average curvature are respectively located between the intervals from 0.17 to 0.26h 1 , 0.17 to 0.26h 1 , and 0.2 to 0.35h 1 above the bottom end.…”

Experimental study of ring-shaped steel plate shear walls

“…The structural tests were stopped when either the floor story drift angle exceeded 6%, or if the strength of the specimen degraded to a value less than 80% of it's ultimate strength. Drift angle (% rad) 0.375 0.5 0.75 1 1.5 2.0 3.0 4.0 5.0 6.0 Number of cycles 3 3 3 3 2 2 2 2 2 2 Cyclic displacements used by Li et al (2010) were imposed according to the loading history (Figure 19), starting from small drift and increasing to 5%. The first three peak displacements were repeated for three times, next 10 peak displacements were repeated for 2 times.…”