1、Designation: F734 95 (Reapproved 2011)F734 17Standard 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 ca
2、se of revision, 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 Fsy and shear ultimate strength Fsu of fu
3、sion bonds in polycarbonateby applying torsional shear loads to the fusion-bond line.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices an
4、d determine the applicability of regulatorylimitations prior to use.1.3 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommenda
5、tions issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.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
6、same material using heat and pressure.3.1.2 shear, ninternal force tangential to the section on which it acts.3.1.3 shear strength, nthe maximum allowable stress in a body resulting from forces which tend to cause two contiguous partsof the body to slide relative to each other in a direction paralle
7、l to their plane of contact.3.1.4 torsional shear fixture, na device used to apply a shear force in the circular section of the test specimen to produce aperipherally uniform stress distribution.4. Summary of Test Method4.1 Test specimens are prepared with a fusion bond at the center of a polycarbon
8、ate laminate joined to two metal test blocks.A twisting action is applied to one block and the load required to fracture the fusion bond is transformed into the torsional shearstrength of the fusion bond.1 This practice is under the jurisdiction of ASTM Committee F07 on Aerospace and Aircraft and is
9、 the direct responsibility of Subcommittee F07.08 on TransparentEnclosures and Materials.Current edition approved Dec. 1, 2011June 1, 2017. Published April 2012June 2017. Originally approved in 1981. Last previous edition approved in 20062011 as F734 95(2006).F734 95(2011). DOI: 10.1520/F0734-95R11.
10、10.1520/F0734-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is
11、 intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the
12、current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Significance and Use5.1 At this writing, aerospace quality extruded transparent polycarbo
13、nate material is not available in thicknesses greater than0.5 in. (12.7 mm). When a requirement exists for sheets thicker than 0.5 in. (12.7 mm), two or more sheets are fusion bondedtogether to form a single sheet of the desired thickness.5.2 The structural integrity of the completed transparency de
14、pends on the integrity of the fusion bond. This test applies torsionalshear loads to measure the structural integrity of the fusion bond. This test method is considered more reliable and morereproducible than shear tests in tension or compression.6. ApparatusNOTE 1A standard torsional test machine m
15、ay be substituted is a suitable substitute for the apparatus described in this section. The machine shallhave variable angular displacement rates from 8 to 800/min. (0.14 to 14 rad/min.). If a torsional test machine is used, the calibration and standardizationin Section 8 shouldshall be disregarded.
16、6.1 Torsional Shear FixtureIllustrations of the fixture are shown in Figs. 1 and 2.6.2 Calibration Load ArmA lever arm with a load pan shall be provided for purposes of calibrating the torsional shearapparatus.FIG. 1 Torsional Shear Test Fixture (All Dimensions in Inches)F734 1726.3 Universal Testin
17、g MachineAn autographically recording universal tensile testing machine shall be used to apply aconstant rate of rotation to the torsional shear fixture by means of the loading cable. The machine shall have variable crossheadrates (from 0.2 in./min 5.08 mm/min to 20 in./min 508 mm/min.), and a calib
18、rated load measurement mechanism usable in arange from 0 to 200 lb (0 to 90 kg) in tension.6.4 Calibrated Spring Scales, 0 to 10 lb (4.54 kg) 6 1 %, are required for calibration purposes.7. Test Specimens and Sample7.1 Machine test specimens to the geometry shown in Fig. 3. Machine specimens at less
19、 than 1-m (3.28-ft)/s surface velocityto avoid heat buildup during machining. Position the groove such that the fusion bond lies at the minimum diameter of the groove.The groove shall have a 125-in. (3-m) finish.7.2 Test a minimum of five specimens from each fusion bonded sheet. Sheets with multiple
20、 fusion bonds shall have five testspecimens tested for each fusion bond interface.8. Calibration and Standardization8.1 Attach the torsional shear fixture securely to the base of the test machine.8.2 Attach the calibration load arm to the rotatable shaft and tighten screw to preclude slippage. See F
21、ig. 4.8.3 Determine the equivalent weight of the calibrating arm at the load pan with no torsional resistance in the apparatus and withthe load arm level. This load is L0.8.4 Measure the lever arm, D, in inches to 61 % accuracy between the shaft center and the load pan pivot point.8.5 Calculate L1 =
22、 (200D) L0.8.6 Attach the loading cable to the testing machine load-weighing mechanism.8.7 Place a weight equal to L1 in the calibrating arm load pan and note reading L2 on the testing machine weighing mechanism;L2 is equivalent to 200 in. lb (22.6 N-m) of torque. Calculate a conversion factor K, K
23、= (200/L2).8.8 Remove calibration load arm from the torsional shear test fixture.9. Conditioning9.1 Unless otherwise specified, condition the test specimens in accordance with Procedure A of Practice D618.FIG. 2 Torsional Shear Test FixtureF734 17310. Procedure10.1 Measure the diameter (d) of each s
24、pecimen at the groove 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 specimen ultimate, L4, and autographically
25、determine load rate L/t andangular strain rate, , in the straight line portion of the autographic curve. Calculate the torsional loads T3 = KL3 and 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,
26、 T/t,and angular strain rate, , in the straight line portion of the autographic curve.11. Calculation11.1 The shear yield stress Fsy, and shear ultimate stress Fsu in pounds per square inch, are calculated by the formula:Fsy516T3/pid3,Fsu516T4/pid3 (1)12. Report12.1 The report shall include complete
27、 identification of the material (manufacturer and thickness), test date, whether a torsionaltest machine or a tensile test machine was used, d, , Fsy, Fsu , and shall note the failure mechanism of each specimen, tearingof the polycarbonate, cleaving of the fusion bond, or an estimate of the relative
28、 percentage of each.13. Precision and Bias13.1 PrecisionThis test method does not yet contain a numerical precision statement. The precison of this test method is underinvestigation by a task group of Subcommittee F07.08 via an interlaboratory study.Anyone wishing to participate in this work maycont
29、act the Chairman, Subcommittee F07.08, ASTM, 100 Barr Harbor Dr., PO Box C700, West Conshohocken, PA 19428-2559.13.2 BiasSince there is no acceptable reference material suitable for determining the bias for the procedure in this test methodto determine shear strength of fusion bonded polycarbonate,
30、bias has not been determined.14. Keywords14.1 fusion bonded polycarbonate; shear strength; torsionFIG. 3 Torsional Shear Test SpecimenF734 174ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of thi
31、s 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 responsible technical committee and must be reviewed every five yea
32、rs 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 consideration at a meeting of theresponsible technical committ
33、ee, 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, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428
34、-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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 4 Calibration Load ArmF734 175
