1、Designation: F734 95 (Reapproved 2011)Standard Test Method forShear Strength of Fusion Bonded Polycarbonate AerospaceGlazing Material1This standard is issued under the fixed designation F734; the number immediately following the designation indicates the year of originaladoption or, in the case of r
2、evision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method determines the shear yield strength Fsyand shear ultimate strength Fsuof fusion bond
3、s in polycarbon-ate by applying torsional shear loads to the fusion-bond line.1.2 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 and health practices and deter
4、mine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for Testing3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 fusion bond, nthe bonding of two pieces of the samematerial using heat a
5、nd pressure.3.1.2 shear, ninternal force tangential to the section onwhich it acts.3.1.3 shear strength, nthe maximum allowable stress in abody resulting from forces which tend to cause two contiguousparts of the body to slide relative to each other in a directionparallel to their plane of contact.3
6、.1.4 torsional shear fixture, na device used to apply ashear force in the circular section of the test specimen toproduce a peripherally uniform stress distribution.4. Summary of Test Method4.1 Test specimens are prepared with a fusion bond at thecenter of a polycarbonate laminate joined to two meta
7、l testblocks. A twisting action is applied to one block and the loadrequired to fracture the fusion bond is transformed into thetorsional shear strength of the fusion bond.5. Significance and Use5.1 At this writing, aerospace quality extruded transparentpolycarbonate material is not available in thi
8、cknesses greaterthan 0.5 in. (12.7 mm). When a requirement exists for sheetsthicker than 0.5 in. (12.7 mm), two or more sheets are fusionbonded together to form a single sheet of the desired thickness.5.2 The structural integrity of the completed transparencydepends on the integrity of the fusion bo
9、nd. This test appliestorsional shear loads to measure the structural integrity of thefusion bond. This test method is considered more reliable andmore reproducible than shear tests in tension or compression.6. ApparatusNOTE 1A standard torsional test machine may be substituted for theapparatus descr
10、ibed in this section. The machine shall have variableangular displacement rates from 8 to 800/min. (0.14 to 14 rad/min.). If atorsional test machine is used, the calibration and standardization inSection 8 should be disregarded.6.1 Torsional Shear FixtureIllustrations of the fixture areshown in Figs
11、. 1 and 2.6.2 Calibration Load ArmA lever arm with a load panshall be provided for purposes of calibrating the torsional shearapparatus.6.3 Universal Testing MachineAn autographically re-cording universal tensile testing machine shall be used to applya constant rate of rotation to the torsional shea
12、r fixture bymeans of the loading cable. The machine shall have variablecrosshead rates (from 0.2 in./min 5.08 mm/min to 20 in./min508 mm/min.), and a calibrated load measurement mecha-nism usable in a range from 0 to 200 lb (0 to 90 kg) in tension.6.4 Calibrated Spring Scales, 0 to 10 lb (4.54 kg) 6
13、 1%,are required for calibration purposes.1This practice is under the jurisdiction of ASTM Committee F07 on AerospaceandAircraft and is the direct responsibility of Subcommittee F07.08 on TransparentEnclosures and Materials.Current edition approved Dec. 1, 2011. Published April 2012. Originallyappro
14、ved in 1981. Last previous edition approved in 2006 as F734 95 (2006).DOI: 10.1520/F0734-95R11.2For 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 Documen
15、t Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Test Specimens and Sample7.1 Machine test specimens to the geometry shown in Fig.3. Machine specimens at less than 1-m (3.28-ft)/s surfacevelocity t
16、o avoid heat buildup during machining. Position thegroove such that the fusion bond lies at the minimum diameterof the groove. The groove shall have a 125-in. (3-m) finish.7.2 Test a minimum of five specimens from each fusionbonded sheet. Sheets with multiple fusion bonds shall have fivetest specime
17、ns tested for each fusion bond interface.8. Calibration and Standardization8.1 Attach the torsional shear fixture securely to the base ofthe test machine.8.2 Attach the calibration load arm to the rotatable shaft andtighten screw to preclude slippage. See Fig. 4.8.3 Determine the equivalent weight o
18、f the calibrating armat the load pan with no torsional resistance in the apparatus andwith the load arm level. This load is L0.8.4 Measure the lever arm, D, in inches to 61 % accuracybetween the shaft center and the load pan pivot point.8.5 Calculate L1= (200/D)L0.8.6 Attach the loading cable to the
19、 testing machine load-weighing mechanism.8.7 Place a weight equal to L1in the calibrating arm loadpan and note reading L2on the testing machine weighingmechanism; L2is equivalent to 200 in. lb (22.6 N-m) of torque.Calculate a conversion factor K, K = (200/L2).8.8 Remove calibration load arm from the
20、 torsional sheartest fixture.FIG. 1 Torsional Shear Test Fixture (All Dimensions in Inches)F734 95 (2011)29. Conditioning9.1 Unless otherwise specified, condition the test specimensin accordance with Procedure A of Practice D618.10. Procedure10.1 Measure the diameter (d) of each specimen at thegroov
21、e root to 61 % accuracy.10.2 Insert the test specimen into the test specimen grips.10.3 Set crosshead separation to cause 360 (6.283 radians)rotation in the apparatus within 60 6 10 s.10.4 Record load at specimen yield, L3, and load at speci-men ultimate, L4, and autographically determine load rateD
22、L/Dt and angular strain rate, v, in the straight line portion ofthe autographic curve. Calculate the torsional loads T3= KL3and T4= KL4.NOTE 2If a torsional test machine is used, record the yield torque, T3,and the ultimate torque, T4, and autographically determine torque rate,DT/Dt, and angular str
23、ain rate, v, in the straight line portion of theautographic curve.11. Calculation11.1 The shear yield stress Fsy, and shear ultimate stress Fsuin pounds per square inch, are calculated by the formula:Fsy5 16T3/pd3, Fsu5 16T4/pd3(1)12. Report12.1 The report shall include complete identification of th
24、ematerial (manufacturer and thickness), test date, whether atorsional test machine or a tensile test machine was used, d, v,Fsy,Fsu, and shall note the failure mechanism of each speci-men, tearing of the polycarbonate, cleaving of the fusion bond,or an estimate of the relative percentage of each.FIG
25、. 2 Torsional Shear Test FixtureFIG. 3 Torsional Shear Test SpecimenF734 95 (2011)313. Precision and Bias13.1 PrecisionThis test method does not yet contain anumerical precision statement. The precison of this test methodis under investigation by a task group of Subcommittee F07.08via an interlabora
26、tory study. Anyone wishing to participate inthis work may contact the Chairman, Subcommittee F07.08,ASTM, 100 Barr Harbor Dr., PO Box C700, West Consho-hocken, PA 19428-2559.13.2 BiasSince there is no acceptable reference materialsuitable for determining the bias for the procedure in this testmethod
27、 to determine shear strength of fusion bonded polycar-bonate, bias has not been determined.14. Keywords14.1 fusion bonded polycarbonate; shear strength; torsionFIG. 4 Calibration Load ArmF734 95 (2011)4ASTM International takes no position respecting the validity of any patent rights asserted in conn
28、ection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the respons
29、ible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful c
30、onsideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 10
31、0 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F734 95 (2011)5
