1、Designation: E 2126 07Standard Test Methods forCyclic (Reversed) Load Test for Shear Resistance of Wallsfor Buildings1This standard is issued under the fixed designation E 2126; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the evaluation of the shearstiffness, shear strength, and ductility of a wall assembl
3、y,including applicable shear connections and hold-down connec-tions, under quasi-static cyclic (reversed) load conditions.1.2 These test methods are intended for wall assembliesconstructed from wood or metal framing with solid sheathingor other bracing methods or structural insulated panels.1.3 The
4、values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated w
5、ith its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 2395 Test Methods for Specific Gravity of Wood andWood-Based Ma
6、terialsD 4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Base MaterialsD 4444 Test Methods for Use and Calibration of Hand-HeldMoisture MetersE 564 Practice for Static Load Test for Shear Resistance ofFramed Walls for BuildingsE 575 Practice for Reporting Data from Struct
7、ural Tests ofBuilding Constructions, Elements, Connections, and As-sembliesE 631 Terminology of Building Constructions2.2 International Organization for Standardization Stan-dard:ISO 16670:2003 Timber StructuresJoints Made with Me-chanical FastenersQuasi-static Reversed-cyclic TestMethod33. Terminol
8、ogy3.1 For definitions of terms used in this standard, seeTerminology E 631.3.2 Definitions of Terms Specific to This Standard:3.2.1 ductility factor, monotonic (), nthe ratio of theultimate displacement (Dm) and the yield displacement (Dyield)observed in monotonic test.3.2.2 ductility ratio, cyclic
9、 (D), nthe ratio of the ultimatedisplacement (Du) and the yield displacement (Dyield) observedin cyclic test.3.2.3 elastic shear stiffness (Ke) (see 9.1.4, Fig. 2), ntheresistance to deformation of a wall in the elastic range beforethe first major event (FME) is achieved, which can beexpressed as a
10、slope measured by the ratio of the resisted shearload to the corresponding displacement.3.2.4 envelope curve (see Fig. 1), nthe locus of extremi-ties of the load-displacement hysteresis loops. The envelopecurve contains the peak loads from the first cycle of each phaseof the cyclic loading. Wall dis
11、placement in the positivedirection produces a positive envelope curve; the negative walldisplacement produces a negative envelope curve. The positivedirection is based on outward movement of the hydraulicactuator.3.2.5 equivalent energy elastic-plastic (EEEP) curve (see9.1.4, Fig. 2), nan ideal elas
12、tic-plastic curve circumscribingan area equal to the area enclosed by the envelope curvebetween the origin, the ultimate displacement, and the dis-placement axis. For monotonic tests, the observed load-displacement curve is used to calculate the EEEP curve.3.2.6 failure limit state, nthe point on th
13、e envelope curvecorresponding to the last data point with the absolute loadequal or greater than |0.8 Ppeak|, as illustrated in Fig. 2a.3.2.7 failure load (Pu), nthe load corresponding to thefailure limit state.3.2.8 first major event (FME), nthe first significant limitstate to occur (see limit stat
14、e).1These test methods are under the jurisdiction of ASTM Committee E06 onPerformance of Buildings and are the direct responsibility of Subcommittee E06.11on Horizontal and Vertical Structures/Structural Performance of Completed Struc-tures.Current edition approved June 1, 2007. Published June 2007.
15、 Originallyapproved in 2001. Last previous edition approved in 2005 as E 2126 052For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page
16、onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.FIG. 1 Examples of Observed Hysteresis
17、Curve and Envelope Curves for Method AFIG. 1 Examples of Observed Hysteresis Curve and Envelope Curves for Method B (continued)E21260723.2.9 limit state, nan event that demarks the two behaviorstates, at which time some structural behavior of the element orsystem is altered significantly.3.2.10 stab
18、ilized response, nload resistance that differsnot more than 5 % between two successive cycles at the sameamplitude.3.2.11 strength limit state (see Fig. 2), nthe point on theenvelope curve corresponding to the maximum absolute dis-placement Dpeakat the maximum absolute load (Ppeak) resistedby the as
19、sembly.3.2.12 ultimate displacement, cyclic (Du), nthe displace-ment corresponding to the failure limit state in cyclic test.3.2.13 ultimate displacement, monotonic (Dm), nthe dis-placement corresponding to the failure limit state in monotonictest.3.2.14 yield limit state, nthe point in the load-dis
20、placement relationship where the elastic shear stiffness ofthe assembly decreases 5 % or more. For assemblies withnonlinear ductile elastic response, the yield point (Dyield, Pyield)is permitted to be determined using the EEEP curve (see 9.1.4).4. Summary of Test Method4.1 The elastic shear stiffnes
21、s, shear strength and ductility ofwalls are determined by subjecting a wall assembly to full-reversal cyclic racking shear loads. This is accomplished byanchoring the bottom edge of the wall assembly to a rigid baseand applying a force parallel to the top of the wall. The testassembly is allowed to
22、displace in its own plane. As the wallassembly is racked to specified displacement increments, theracking (shear) load and displacements are continuously mea-sured (see 8.7).5. Significance and Use5.1 These test methods are intended to measure the perfor-mance of walls subjected to earthquake loads.
23、 Since theseloads are cyclic, the loading process simulates the actions andtheir effects on the walls.6. Wall Assembly6.1 GeneralThe typical wall assembly consists of a frameon which the elements comprising the wall, including thesheathing (or diagonal bracing members, if applicable) areplaced. The
24、elements shall be fastened to the frame in a mannerto conform to 6.2. Elements used to construct wall assembliesmay be varied to permit anticipated failure of selected ele-ments.6.2 ConnectionsThe performance of framed walls is in-fluenced by the type, spacing, and edge distance of fastenersattachin
25、g sheathing to framing and spacing of the shearconnections and hold-down connectors to the rigid base. All ofthese connections shall be consistent with the types used inactual building connections.6.3 Frame RequirementsThe frame of the wall assemblyshall consist of materials representative of those
26、to be used inFIG. 1 Examples of Observed Hysteresis Curve and Envelope Curves for Method C (continued)E2126073the actual building construction. The connections of thesemembers shall be consistent with those intended in actualbuilding construction.6.3.1 For wood framing members, record the species an
27、dgrade of lumber used; moisture content of lumber at the time offabrication and testing, if more than 24 h passes between theseoperations (see Test Methods D 4442, Method A or B; orD 4444, Method A or B); and specific gravity of the lumber(see Test Methods D 2395, Method A).6.3.2 For steel or other
28、metal framing members, record thematerial specifications and thickness.6.4 Structural Insulated PanelThe panel is prefabricatedassembly consisting of an insulating core of 1.5 in. (38 mm)minimum sandwiched between two facings. The assembly isconstructed by attaching panels together and to top and bo
29、ttomplates or tracks.6.5 Wall SizeThe wall assembly shall have a height andlength or aspect (height/length) ratio that is consistent withintended use requirements in actual building construction (seeFig. 3).7. Test Setup7.1 The wall assembly shall be tested such that all elementsand sheathing surfac
30、es are observable. For assemblies such asframed walls with sheathing on both faces of framing orframeless structural insulated panels, the assemblies are dis-mantled after tests to permit observation of all elements. Thebottom of the wall shall be attached to a rigid base as specifiedin 6.2. The tes
31、t apparatus shall support the wall assembly asnecessary to prevent displacement from the plane of the wall,but in-plane displacement shall not be restricted.8. Procedure8.1 Number of TestsA minimum of two identical wallassemblies shall be tested to determine the elastic shearstiffness and shear stre
32、ngth of a given construction. Thesevalues shall be calculated in accordance with 3.2 and 9.1. Foranalysis, the mean values are permitted to be based on theresults of two walls if the parameters are within 10 % of eachother. Otherwise, the mean values shall be based on the resultsof at least three wa
33、lls.8.2 Apply racking shear load horizontally in the plane of thewall to the top of the wall assembly (along the axis) (Fig. 4)using a programmable double-acting hydraulic actuator withload cell. The cyclic displacement of the actuator shall becontrolled to follow a cyclic displacement procedure des
34、cribedin either 8.3 (Method A), 8.4 (Method B), or 8.5 (Method C).8.3 Method A (Sequential-Phased Displacement Proce-dure):8.3.1 Sequential Phased Displacement (SPD) LoadingProtocolDisplacement-controlled loading procedure that in-volves displacement cycles grouped in phases at incrementallyincreasi
35、ng displacement levels. The cycles shall form either asinusoidal wave or a triangular wave. The SPD loadingFIG. 2 Performance Parameters of Shear-Wall Assembly: (A) Last Point at Pu$ 0.8 PpeakE2126074consists of two displacement patterns and is illustrated in Fig.5. The first displacement pattern co
36、nsists of three phases, eachcontaining three fully-reversing cycles of equal amplitude, atdisplacements representing 25 %, 50 %, and 75 % of antici-pated FME. The second displacement pattern is illustrated inFig. 6. Each phase is associated with a respective displacementlevel and contains one initia
37、l cycle, three decay cycles, and anumber of stabilization cycles. For nailed wood-frame shearwalls, three stabilization cycles are sufficient to obtain astabilized response. The amplitude of each consecutive decaycycle decreases by 25 % of the initial displacement.8.3.2 The schedule of amplitude inc
38、rements between thesequential phases is given in Table 1. The amplitude incre-ments selected for the SPD procedure are based on the FMEand the ductility factor, , determined from the static mono-tonic load test on an identical wall assembly in accordance withPractice E 564. To determine Dmand Dyield
39、, it is permitted tocompute EEEP curves, based on monotonic test data, inaccordance with 9.1.4.8.4 Method B (ISO 16670 Protocol):8.4.1 ISO Displacement ScheduleDisplacement-controlled loading procedure that involves displacement cyclesgrouped in phases at incrementally increasing displacementlevels.
40、 The ISO loading schedule consists of two displacementpatterns and is illustrated in Fig. 7. The first displacementpattern consists of five single fully reversed cycles at displace-ments of 1.25 %, 2.5 %, 5 %, 7.5 %, and 10 % of the ultimatedisplacement Dm. The second displacement pattern consists o
41、fphases, each containing three fully reversed cycles of equalamplitude, at displacements of 20 %, 40 %, 60 %, 80 %,100 %, and 120 % of the ultimate displacement Dm.8.4.2 The sequence of amplitudes, which is given in Table 2,are a function of the mean value (where applicable) of theultimate displacem
42、ent (Dm) obtained from matched wall speci-mens in the monotonic tests in accordance with Practice E 564.8.5 Method C (CUREE Basic Loading Protocol):8.5.1 CUREE Basic Loading ProtocolDisplacement-controlled loading procedure that involves displacement cyclesgrouped in phases at incrementally increasi
43、ng displacementlevels. The loading history starts with a series of initiationcycles at small amplitudes of equal magnitude. Further, eachphase of the loading history consists of a primary cycle withamplitude expressed as a fraction (percent) of the referencedeformation, D, and subsequent trailing cy
44、cles with amplitudeof 75 % of the primary one.NOTE 1Normally, six initiation cycles of equal amplitude serve tocheck loading equipment, measurement devices, and the force-deformation response at small amplitudes.8.5.2 The schedule of amplitude increments is given inTable 3 and is illustrated in Fig.
45、 8. The reference deformationD shall be an estimate of the maximum displacement at whichthe load in a primary cycle has not yet dropped below 0.8 Ppeak.If the panel has not failed at the end of Phase 8 of Table 3, thenFIG. 2 Performance Parameters of Shear-Wall Assembly: (B) Last Point at Pu=0.8Ppea
46、k(continued)E2126075additional phases shall be added. Each subsequent phase shallconsist of a primary cycle with an increase in amplitude of a(a # 0.5) over the previous primary cycle, and followed bytwo trailing cycles with amplitude of 75 % of the primary one.8.6 The actuator displacement in Metho
47、ds A, B, or C shallbe controlled at either constant cyclic frequency or at aconstant rate of displacement. The rate of displacement shall bebetween 0.04 and 2.5 in./s (1.0 and 63.5 mm/s). The cyclicfrequency shall range from 0.2 to 0.5 Hz to avoid inertialeffects of the mass of the wall and test fix
48、ture hardware duringcyclic loading. The loading shall follow the correspondingprocedure until the applied load diminishes more than 0.2Ppeak, that is, until the failure limit state occurs.8.7 Displacements shall be measured with displacementmeasuring devices with a resolution of 0.005 in. (0.13 mm)
49、orother suitable devices for continuously measuring displace-ment under cyclic loading conditions, at a minimum samplingrate of 100 readings per cycle. The following instrumentationshall be provided for measuring displacements, and hold-downconnector forces when required:8.7.1 Horizontal displacement of the wall at the top plate.8.7.2 Vertical displacement of both end posts (uplift andcompression) relative to the rigid base. The reference point forthis measurement shall be on or immediately adjacent to theoutside face of the end post.8.7.3 Horizontal di
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