1、Designation:F73495(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 revisi
2、on,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 bonds in poly
3、carbon-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 determine the app
4、lica-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 and pressure.3.1
5、.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.3.1.4 torsional sh
6、ear 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 metal testblocks.A twis
7、ting 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 thicknesses greaterthan 0
8、.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 bond.This test appliestorsio
9、nal 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.ApparatusNOTE1A standard torsional test machine may be substituted for theapparatus described in this section.The machi
10、ne 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.1 and 2.6.2 Calibration Load ArmA
11、 lever arm with a load panshall be provided for purposes of calibrating the torsional shearapparatus.6.3 Universal Testing MachineAn autographically record-ing universal tensile testing machine shall be used to apply aconstant rate of rotation to the torsional shear fixture by meansof the loading ca
12、ble.The machine shall have variable cross-head rates(from 0.2 in./min 5.08 mm/min to 20 in./min 508mm/min.),and a calibrated load measurement mechanismusable 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 1%,are required for calibration purposes.1
13、This practice is under the jurisdiction of ASTM Committee F07 on Aerospaceand Aircraft and is the direct responsibility of Subcommittee F07.08 on TransparentEnclosures and Materials.Current edition approved Dec.1,2011.Published April 2012.Originallyapproved in 1981.Last previous edition approved in
14、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 Document Summary page onthe ASTM website.Copyright ASTM Inter
15、national,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 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 to avoid heat buildup during machining.Position thegroove such
16、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 specimens 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 Det