ASTM_F_736_-_95_2011.pdf

Designation:F73695(Reapproved 2011)Standard Test Method forImpact Resistance of Monolithic Polycarbonate Sheet byMeans of a Falling Weight1This standard is issued under the fixed designation F736;the number immediately following the designation indicates the year of originaladoption or,in the case 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 covers the determination of the energyrequired to initiate failure in monolithic polycarbonate sheetmaterial under specified conditions of impact using a freefalling weight.1.2 Two specimen types are defined as follows:1.2.1 Type A consists of a flat plate test specimen andemploys a clamped ring support.1.2.2 Type B consists of a simply supported three-pointloaded beam specimen(Fig.1)and is recommended for usewith material which can not be failed using the Type Aspecimen.For a maximum drop height of 6.096 m(20 ft)anda maximum drop weight of 22.68 kg(50 lb),virgin polycar-bonate greater than 12.70 mm(12in.)thick will probablyrequire use of the Type B specimen.NOTE1See also ASTM Methods:D1709,D2444 and D3029.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3.1 ExceptionThe inch-pound units in parentheses areprovided for information only.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 and health practices and determine the applica-bility of regulatory limitations prior to use.For specific hazardstatement,See Section 7.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD790 Test Methods for Flexural Properties of Unreinforcedand Reinforced Plastics and Electrical Insulating Materi-als3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 failure(of test specimen)failure is signified by thepresence of any crack or split in the impact-deformed area thatwas created by the impact of the falling weight and that can beseen by the naked eye.4.Summary of Test Method4.1 The test procedure to cause failure covers a range ofimpact energies and differs with respect to geometry andsupport of test specimen Type A and test specimen Type B.Guidelines are established to control drop heights,impactvelocity,drop weights,impactor heads,impactor release,impactor rebound,impact location,and specimen configurationwhich are applicable to a falling weight impact tester designedto accommodate Type A or Type B test specimens,or both,fabricated from monolithic polycarbonate sheet material.5.Significance and Use5.1 This practice is applicable for qualitatively evaluatingcoated and uncoated monolithic polycarbonate sheet material,for monitoring process control,for screening studies,and as anaid in the prediction of hardware performance when exposed toimpact service conditions.5.2 A limitation of Type A specimen testing is that a thicksheet may not fail since the available impact energy is limitedby the maximum drop height and falling weight capacity of thetest apparatus.Use Specimen TypeAfor material less than 12.7mm(0.50 in.)thick.5.3 Within the range of drop heights of this system,testsemploying different velocities are not expected to producedifferent results.However,for a given series of tests,it isrecommended that the drop height be held approximatelyconstant so that velocity of impact(strain rate)will not be avariable.5.4 As the polycarbonate specimen undergoes large plasticdeformation under impact,the down(opposite impact)side is1This test method is under the jurisdiction of ASTM Committee F07 onAerospace and Aircraft and is the direct responsibility of Subcommittee F07.08 onTransparent Enclosures and Materials.Current edition approved Dec.1,2011.Published April 2012.Originallyapproved in 1981.Last previous edition approved in 2006 as F736 95(2006).DOI:10.1520/F0736-95R11.2For 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 International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 under tensile loading and most influential in initiating failure.Polycarbonate sheet coated on one side may yield significantlydifferent test results when tested with the coated side downversus the coated side up.5.5 Direct comparison of specimen Type A and specimenType B test results should not be attempted.For test programsthat will require the comparison of interlaboratory test resultsthe specimen type and the approximate drop height must bespecified.5.6 Monolithic polycarbonate sheet is notch sensitive.Dataobtained from other test methods,particularly