1、Designation: E2126 11 (Reapproved 2018)Standard Test Methods forCyclic (Reversed) Load Test for Shear Resistance of VerticalElements of the Lateral Force Resisting Systems forBuildings1This standard is issued under the fixed designation E2126; the number immediately following the designation indicat
2、es the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the evaluation of th
3、e shearstiffness, shear strength, and ductility of the vertical elementsof lateral force resisting systems, including applicable shearconnections and hold-down connections, under quasi-staticcyclic (reversed) load conditions.1.2 These test methods are intended for specimens con-structed from wood or
4、 metal framing braced with solidsheathing or other methods or structural insulated panels.1.3 The 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 stan
5、dard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior t
6、o use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarri
7、ers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D2395 Test Methods for Density and Specific Gravity (Rela-tive Density) of Wood and Wood-Based MaterialsD4442 Test Methods for Direct Moisture Content Measure-ment of Wood and Wood-Based MaterialsD4444 Test Method for Laboratory
8、 Standardization andCalibration of Hand-Held Moisture MetersE564 Practice for Static Load Test for Shear Resistance ofFramed Walls for BuildingsE575 Practice for Reporting Data from Structural Tests ofBuilding Constructions, Elements, Connections, and As-sembliesE631 Terminology of Building Construc
9、tions2.2 ISO Standard:3ISO 16670 Timber StructuresJoints Made with Mechani-cal FastenersQuasi-static Reversed-cyclic Test Method2.3 Other Standards:4ANSI/AF the negativespecimen displacement produces a negative envelope curve.The positive direction is based on outward movement of thehydraulic actuat
10、or.3.2.4 envelope curve, average(see Fig. 3),nenvelopecurve obtained by averaging the absolute values of load anddisplacement of the corresponding positive and the negativeenvelope points for each cycle.3.2.5 equivalent energy elastic-plastic (EEEP) curve (see9.1.4, Fig. 1),nan ideal elastic-plastic
11、 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 the envelope
12、curvecorresponding to the last data point with the absolute loadequal or greater than |0.8 Ppeak|, as illustrated in Fig. 1.3.2.7 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 state).3.2.9 lim
13、it state, nan event that demarks the two behaviorstates, at which time some structural behavior of the specimenis altered significantly.3.2.10 specimen, nthe vertical element of the lateral forceresisting system to be tested. Example of specimens are walls,structural insulated panels, portal frames,
14、 etc. A specimen canbe a single element or an entire line of resistance within alateral force resisting system.3.2.11 stabilized response, nload resistance that differsnot more than 5 % between two successive cycles at the sameamplitude.3.2.12 strength limit state (see Fig. 1),nthe point on theenvel
15、ope curve corresponding to the maximum absolute dis-placement peakat the maximum absolute load (Ppeak) resistedby the specimen.3.2.13 ultimate displacement, cyclic (u), nthe displace-ment corresponding to the failure limit state in cyclic test.3.2.14 ultimate displacement, monotonic (m), nthe dis-pl
16、acement corresponding to the failure limit state in monotonictest.3.2.15 yield limit state, nthe point in the load-displacement relationship where the elastic shear stiffness ofFIG. 1 Performance Parameters of Specimen: (A) Last Point at Pu$ 0.8 PpeakE2126 11 (2018)2FIG. 1 Performance Parameters of
17、Specimen: (B) Last Point at Pu=0.8Ppeak(continued)FIG. 2 Examples of Observed Hysteresis Curve and Envelope Curves for Test Method AE2126 11 (2018)3the assembly decreases 5 % or more. For specimens withnonlinear ductile elastic response, the yield point (yield, Pyield)is permitted to be determined u
18、sing the EEEPcurve (see 9.1.4).4. Summary of Test Method4.1 The elastic shear stiffness, shear strength and ductility ofspecimens are determined by subjecting a specimen to full-reversal cyclic racking shear loads. This is accomplished byanchoring the bottom edge of the specimen to a test basesimula
19、ting intended end-use applications and applying a forceparallel to the top of the specimen. The specimen is allowed todisplace in its plane. Sheathing panels that are a component ofa specimen shall be positioned such that they do not bear on thetest frame during testing. (See Note 1.) As the specime
20、n isracked to specified displacement increments, the racking(shear) load and displacements are continuously measured (see8.7).NOTE 1If the end-use applications require sheathing panels beardirectly on the sill plate, such as most structural insulated panels, thespecimen may be tested with sheathing
21、panels that bear on the sill plate.5. Significance and Use5.1 These test methods are intended to measure the perfor-mance of vertical elements of the lateral force resisting systemsubjected to earthquake loads. Since these loads are cyclic, theloading process simulates the actions and their effects
22、on thespecimens.6. Specimen6.1 GeneralThe typical specimen consists of a frame,bracing elements, such as panel sheathing, diagonal bracing,etc., and fastenings. The bracing is attached on one side of theframe unless the purpose of the test requires bracing on bothsides. The elements of the specimen
23、shall be fastened to theframe in a manner to conform to 6.2. Elements used toconstruct specimens may be varied to permit anticipated failureof selected elements. All detailing shall be clearly identified inthe report in accordance with Section 10.6.2 ConnectionsThe performance of specimens is influ-
24、enced by the type, spacing, and edge distance of fastenersattaching sheathing to framing and spacing of the shearconnections and hold-down connectors, if applicable, and thetightness of the fasteners holding the specimen to the test base.6.2.1 Sheathing Panel AttachmentsAll panel attachmentsshall be
25、 consistent with the types used in actual buildingconstruction. Structural details, such as fastener schedules,fastener edge distance, and the gap between panels, shall bereported in accordance with Section 10.6.2.2 Attachment to the Test BaseSpecimen shall be at-tached to the test base with fastene
26、rs in a manner representingfield conditions. For intended use requirements over a non-rigid foundation, a mock-up flexible base shall be constructedto simulate field conditions. Consideration shall be given to theorientation and type of floor joists relative to the orientation ofFIG. 2 Examples of O
27、bserved Hysteresis Curve and Envelope Curves for Test Method B (continued)E2126 11 (2018)4FIG. 2 Examples of Observed Hysteresis Curve and Envelope Curves for Test Method C (continued)FIG. 3 Example of Average Envelope Curve (see Fig. 2, Test Method C)E2126 11 (2018)5the wall assembly. When strap co
28、nnections are used, they shallbe installed (that is, inside/outside the sheathing, etc.) withoutpre-tension in a configuration that simulates the field applica-tion. The test report shall include details regarding this attach-ment.6.2.3 Anchor and Hold-Down BoltsWhen the specimenframe is made of sol
29、id wood or wood-based composites, theanchor bolts shall be tightened to no more than finger tight plusa18 turn, provided that the design value of stress perpendicularto the grain is not exceeded (see Note 2). The hold-down boltsshall be tightened consistently between replicates in accor-dance with h
30、old-down manufacturers recommendation. Theassembly test shall not start within 10 min of the anchor bolttightening to allow for stress relaxation of the anchor.NOTE 2Since solid wood and wood-based composites relax over timeas well as potentially shrink due to changing moisture content, the intentof
31、 the finger tight plus a18 turn is to avoid any significant pre-tension onthe anchor bolts, which may affect the test results. It is the committeejudgment that the maximum bolt tension should not be more than 300 lbf(1.33 kN) for the purpose of ensuring the bolt is not caught on a thread ornot seate
32、d fully. It should be noted that, however, the bolt tension dependson wood species and density, bolt thread pitch (or bolt diameter), and platewasher size. A general rule of thumb is to finger-tight plus18 turn, whichwill result in a nut displacement of approximately 0.01 in. (0.254 mm) for12 and58-
33、in.-diameter (12.7 and 15.9-mm-diameter) UNC bolts. A torqueof about 50 lbf-in. (5.65 kN-mm) without bolt lubrication would normallyproduce 300 lbf (1.33 kN) of bolt tension.6.3 Frame RequirementsThe frame of the specimen shallconsist of materials representative of those to be used in theactual buil
34、ding construction. The connections of these mem-bers shall be consistent with those intended in actual buildingconstruction.6.3.1 For wood framing members, record the species andgrade of lumber used (or the relevant product identificationinformation for structural composite lumber framing); moisture
35、content of the framing members at the time of the specimenfabrication and testing, if more than 24 h passes between theseoperations (see Test Methods D4442, Test Methods A or B; orD4444, Test Methods A or B); and specific gravity of theframing members (see Test Methods D2395, Test Method A).The spec
36、ific gravity of the framing members shall be repre-sentative of the published specific gravity for the product withno individual member exceeding the published value by morethat 10 % (see ANSI/AF andL = length of specimen, ft (m).9.1.2 Secant shear modulus, G,at0.4Ppeakand at Ppeakshall be calculate
37、d as follows:G 5P3HL(2)where:G = shear modulus of the specimen obtained from test(includes shear and uplift deformation for the connec-tion system), lbf/in. (N/m); represents the secant shearstiffness at specified specimen displacements times theaspect ratio;P = applied load measured at the top edge
38、 of the specimen,lbf (N); = displacement of the top edge of the specimen based ontest, in. (m). This includes both the shear deflection ofthe sheathing material and its connections, and thecontribution of the shear and hold-down connectionsystems;H = height of specimen, ft (m); andL = length of spec
39、imen, ft (m).9.1.3 Cyclic ductility ratio, D, as described in 3.2.1, shall becalculated. If the shear stiffness (shear modulus) at 0.4 Ppeakisgreater than that at Ppeak, generate the EEEPcurve as describedin 9.1.4. Otherwise, the FME and the ultimate displacementshall be determined directly from the
40、 envelope curve. Calculatevalues of displacement, shear forces, and shear modulus at theyield limit state and strength limit state.TABLE 3 Test Method CAmplitude of Primary CyclesPattern StepMinimumNumberof CyclesAmplitude of PrimaryCycle, % 11 6 522 7 7.37 1034 4 254 3046 3 473 708 3 1009 3 100 + 1
41、00A10 3 Additional increments of100 (until specimen failure)A # 0.5.E2126 11 (2018)119.1.4 When specified by 9.1.3, develop an EEEP curve torepresent the envelope curve. Fig. 1 illustrates typical EEEPcurve. The elastic portion of the EEEP curve contains theorigin and has a slope equal to the elasti
42、c shear stiffness, Ke.The plastic portion is a horizontal line equal to Pyielddeter-mined by the following equation:Pyield5 Su2 u222AKeD Ke(3)If u2,2AKe, it is permitted to assume Pyield5 0.85 Ppeakwhere:Pyield= yield load, lbf (N);A = the area under envelope curve from zero to ultimatedisplacement
43、(u) of the specimen, lbfin. (Nm);Ppeak= maximum absolute load resisted by the specimen inthe given envelope, lbf (N);e= displacement of the top edge of the specimen at 0.4Ppeak, in. (mm); andKe= 0.4 Ppeak/e.9.1.4.1 To generate an EEEP curve as described in 8.3.2based on monotonic test results, the p
44、rocedures in this sectionare permitted, with msubstituting for u.9.1.5 If the envelope curve contains data points at loads lessthan |0.8 Ppeak| (past strength limit state), the failure limit stateshall be determined at 0.8 Ppeakusing linear interpolation, asillustrated in Fig. 1.10. Report10.1 The r
45、eport shall include the following information:10.1.1 Date of the test and of report.10.1.2 Names of the test sponsors and test agency and theirlocations.10.1.3 Identification of the specimen (test number, and soforth).10.1.4 Detailed description of the specimen and the testsetup, including the follo
46、wing:10.1.4.1 Dimensions of the specimen.10.1.4.2 Details of the physical characteristics or structuraldesign, or both, of the specimen, including, if applicable, thetype, spacing, and edge distance of fasteners attaching sheath-ing to framing.10.1.4.3 Details of attachment of the specimen in the te
47、stfixture, including a description of the test base and whethersheathing panels are directly bearing on the sill plate duringtesting.10.1.4.4 Location of load application and load cell, straingauges, deflection gauges, and other items for test as appli-cable.10.1.4.5 Description of construction mate
48、rials (for example,material type and grade, thickness, yield point, tensile strength,compressive strength, density, moisture content, manufacturerof components used, source of supply, dimensions, model,type, and other pertinent information, and so forth, as appro-priate for materials used).10.1.4.6
49、Drawing showing plan, elevation, principal crosssection, and other details as needed for description of thespecimen and the test setup (see 10.1.4.1 10.1.4.5).10.1.4.7 Description of general ambient conditions includ-ing the following:(1) At construction;(2) During curing or seasoning, if applicable (includingelapsed time from construction to test); and(3) At test.10.1.4.8 Modifications made on the specimen during test-ing.10.1.4.9 Description of any noted defects existing in thespecimen prior to test.10.1.5 Description of the
