欢迎来到麦多课文档分享! | 帮助中心 海量文档,免费浏览,给你所需,享你所想!
麦多课文档分享
全部分类
  • 标准规范>
  • 教学课件>
  • 考试资料>
  • 办公文档>
  • 学术论文>
  • 行业资料>
  • 易语言源码>
  • ImageVerifierCode 换一换
    首页 麦多课文档分享 > 资源分类 > PDF文档下载
    分享到微信 分享到微博 分享到QQ空间

    ASTM F2108-2006 Standard Practice for Inspection of Transparent Parts by Prism《用棱镜对透光部分的检验用标准实施规程》.pdf

    • 资源ID:537770       资源大小:344.94KB        全文页数:7页
    • 资源格式: PDF        下载积分:5000积分
    快捷下载 游客一键下载
    账号登录下载
    微信登录下载
    二维码
    微信扫一扫登录
    下载资源需要5000积分(如需开发票,请勿充值!)
    邮箱/手机:
    温馨提示:
    如需开发票,请勿充值!快捷下载时,用户名和密码都是您填写的邮箱或者手机号,方便查询和重复下载(系统自动生成)。
    如需开发票,请勿充值!如填写123,账号就是123,密码也是123。
    支付方式: 支付宝扫码支付    微信扫码支付   
    验证码:   换一换

    加入VIP,交流精品资源
     
    账号:
    密码:
    验证码:   换一换
      忘记密码?
        
    友情提示
    2、PDF文件下载后,可能会被浏览器默认打开,此种情况可以点击浏览器菜单,保存网页到桌面,就可以正常下载了。
    3、本站不支持迅雷下载,请使用电脑自带的IE浏览器,或者360浏览器、谷歌浏览器下载即可。
    4、本站资源下载后的文档和图纸-无水印,预览文档经过压缩,下载后原文更清晰。
    5、试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓。

    ASTM F2108-2006 Standard Practice for Inspection of Transparent Parts by Prism《用棱镜对透光部分的检验用标准实施规程》.pdf

    1、Designation: F 2108 06Standard Practice forInspection of Transparent Parts by Prism1This standard is issued under the fixed designation F 2108; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in

    2、parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 Aerospace transparencies undergo high stresses inducedby flight, environmental, or other factors. The transparencyattachment points are especial

    3、ly subject to fatigue. These areasof fatigue are often obstructed or hidden from normal inspec-tion. An inspector, following the techniques described in thispractice, shall use a prism to view damage located neartransparency bolt holes, voids, and delamination that arehidden by edge strips or frames

    4、.1.2 The purpose of this practice is to provide acceptablemethods for performing prism inspections of transparent ma-terials with specific emphasis on aircraft windscreens andcanopies. Caveats and lessons learned from experience areincluded to assist authors in writing tailored inspection instruc-ti

    5、ons for specific applications.1.3 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 limitation

    6、s prior to use.2. Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 coupler, na liquid refractive index-matching agentor wetting agent (for example, glycerol) used to create opticalcontact (coupling) between the prism and transparency.2.1.2 delamination, nthe separation of a lamina

    7、te into itsconstituent parts. An edge delamination is open to the lami-nates free edge. An internal delamination is contained withinthe laminate.2.1.3 edge attachment, nthe means of fastening the sideedges of a transparency to the aircraft structure. Edge attach-ments also include expansion joints a

    8、nd any other connectionbetween the transparency and the aircraft structure.2.1.4 prism, na transparent optical element with polishedplane faces for the entrance and exit sides. Prisms userefraction or internal reflection or both to change the directionof the propagation of light.3. Summary of Practi

    9、ce3.1 Prism inspections shall be performed with the aid of aprism and a wetting agent. The wetting agent is between theprism and transparency to ensure good visibility. The examinerlooks through the prism to see the area of the transparencybelow the prism. The exam is best done without brightsunligh

    10、t, which causes glare. The examiner changes his angleof view and inspects the area seen in the prism. A trained eyecan detect anomalies such as cracks, delaminations, and voids.4. Significance and Use4.1 Prisms are useful tools for viewing areas otherwiseobstructed or hidden from normal viewing. For

    11、 example,transparency bolt holes, voids, and delaminations that arecovered by edge strips or frames can be seen through a prism.The prism, once put against the transparency, with a couplingagent to wet the surfaces, allows viewing of the area belowwhere the prism is placed.5. Apparatus5.1 PrismMater

    12、ial shall be of the same hardness as orsofter than the transparency to avoid scratches. The angles ofthe prism should be set so as to maximize the viewing area. Inthe case of a complex shape, the position of the inspectorshead and potential interference problems shall be considered toensure the insp

    13、ector can look through the prism at the properangles. A typical prism is a 306090 triangle, although theprism does not need to be triangular; it could be a simplerectagon shape.5.2 FlashlightA high output, halogen bulb works best.5.3 CoverTo allow the inspector to shade the inspectionarea if the ins

    14、pection is done in bright sunlight.1This 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 Nov. 1, 2006. Published December 2006. Originallyapproved

    15、 in 2001. Last previous edition approved in 2001 a F 2108 - 01.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Reagents6.1 Use glycerol (USP Grade) as a coupler or wetting agent.6.1.1 The wetting agent shall not harm the transpare

    16、ncy (forexample, cause crazing), shall be clear, and shall have a highenough viscosity to stay in place reasonably well.6.2 Use distilled water.7. Procedure7.1 Use methods shall be approved by the procuring agencyor parts manufacturer. One example is to use a water rinse toclean the area of the tran

    17、sparency thoroughly where the prismwill be placed. Assure the prism is also clean. Any debris willcause scratches to the delicate optical surfaces.7.1.1 Clean the prism with standard optical cleaning solu-tions appropriate for the material from which it is made. SeeNote 1.7.2 If using glycerol, stor

    18、e it in a cool dry place, such as arefrigerator designated for chemicals, so it will be thicker.Apply several drops of coupler to the side of the prism thatgoes against the transparency. Ensure there is enough couplingbetween the prism and transparency to allow a good viewingarea. (WarningDo not all

    19、ow the prism to slide along thetransparency with no wetting agent between them or scratcheswill occur.)7.3 The prism is placed on the transparency and the viewingarea location as shown in Fig. 1. When moving the prism alongthe transparency use light pressure. Do not allow the glycerolto get on the v

    20、iewing surface of the prism, as it will smear theviewing area.7.4 A coupler is required to provide an optical path betweenthe prism and canopy. Placing small amounts (several drops) ofcoupler on both the canopy and the prism tends to work best.Glycerol is a good coupler. The coupler material shall b

    21、ecompatible with the transparency material, the clearer and themore viscous the better. Gentle pressure between the prism andcanopy keeps air out of the coupler and allows the coupler tospread farther. See Note 2.7.5 Gently press the prism (of appropriate size and shape, asdescribed below) to the tr

    22、ansparency. Alter the pressure on theprism corners to remove any trapped air. To keep the prismclean, the least amount of glycerol shall be used. Hold only theedges of the prism and use gentle pressure. (WarningIf thecoupler gets onto the viewing face of the prism, the area ofinterest will be blurre

    23、d. Keep the prisms viewing face clean.)7.6 A light source, such as a flashlight aids in opticalclarification. This inspection technique does not work well inbright sunlight. Bright sunlight causes glare that clouds theviewing area. The inspection works best at night while using aflashlight.NOTE 1Any

    24、 debris will cause scratches to the delicate opticalsurfaces.NOTE 2Using too much coupler will make cleanup more difficult andmake it difficult to keep the prism viewing area clean.7.7 Look through the top of the prism to view the area ofinterest. The prism shall be moved up or down to get theviewin

    25、g area to the proper depth. When looking through theprism, change the angle of view (left to right). Begin to movethe prism along the area of interest. Continue looking throughthe prism, altering angle of view. If an air bubble gets trappedbetween the prism and transparency, gently rock the prism to

    26、completely wet out the surface of the prism and transparency.If more glycerol is needed, lift the prism and add glycerol oradd glycerol just in front of the prism so the prism will slideover the glycerol.7.8 Look through the viewing area of the prism. If the viewdoes not contain the area of interest

    27、, the prism shall be liftedslightly or moved side to side. If the area of interest cannot bebrought into sight, the prism dimensions may need to bealtered. Fig. 1 illustrates how the inspectors eye is able to seeinto the transparency. If the view is hazy, try shading the area.If the view is dark, us

    28、e a flashlight. Note, the angle of view andFIG. 1 Typical Prism Angles (Side View)FIG. 2 Standard NomenclatureF2108062the angle of the flashlight shall be varied to obtain the bestcombination for each inspection.7.9 After inspecting the area in sight, move the prism asrequired to view the entire are

    29、a of interest. Add glycerol to theprism or transparency or both as needed.7.9.1 Photographs shall be taken through the prism view toaid in documentation of findings.8. Guidelines for Interpreting Findings in the PrismView8.1 Bolt Hole InspectionsBolt holes shall be inspected forradial cracks, inner

    30、layer delamination, and the height of a bolthole relative to any edge strips. Figs. 3 and 4 show examplesof how areas over bolt holes can look.8.2 Crack InspectionsCracks can originate from boltholes or where edge strips/edge blocks meet the transparentportion of the transparency. Cracks, by definit

    31、ion, have aphysical gap between the two halves. If a crack occurs whilewet installing a fastener, then sealant can fill the crack. Sealantin a crack will show up as the sealant color or a brownish color.If the crack occurs after the sealant is dry or not in the vicinityof an uncured material, then t

    32、he air in the gap will make thecrack look opaque. Occasionally, the striations and crackdirection can be seen while looking through the prism. Fig. 5shows a side view of cracks stemming from a bolt hole. Fig. 6shows a prism view of a crack.8.3 Delamination InspectionsIn multiple-layer transpar-encie

    33、s, delamination resulting from drilling operations can bedetected. Inner layer delamination can occur in monolithicmaterials. Because of the air gap between inner layers, thedelamination appears cloudy in the prism view.8.4 Void/Resin-Rich InspectionsIf an edge strip is bondedto the transparency, th

    34、e potential for voids and or resin-richareas exists at the bondline. Voids and air bubbles appear clearor cloudy while resin-rich areas are dark as shown in Fig. 7.Voids, air bubbles, and resin-rich areas block the view behindit and thus break up the edge strip pattern. Fig. 8 shows both aresin-rich

    35、 area (on the edge strip) and an air bubble (at the edgeblock bondline). Note that in Fig. 8 the resin-rich area is darkerthan the air bubble and that the edge strip pattern is slightlyvisible behind the resin-rich area but not at all visible below theair bubble. Also, the outline of the prism is se

    36、en at the edges ofthe figure.8.5 Dimensional TolerancesIf inspecting a new transpar-ency, a prism can assist in determining if the correct dimen-sions were met. For example, if the canopy is drilled andfastened to its frame in one operation, the distance from a bolthole to the top of the edge strips

    37、 on both the inside and outsidecan be measured. Or, if a butt block is used, the prisminspection can assure the butt blocks alignment relative to thetransparency and edge strips.FIG. 3 Acceptable Air Bubbles (from Resin Curing)F21080638.6 Bondline ThicknessThough the bondline thickness ofa clear res

    38、in between two clear laminates cannot be easilydistinguished (if at all), the bondline thickness between rein-forced members of the transparency can be distinguished. Forexample, if both edge strips and an edge block are used, thebondline between them (appearing clear) can be determined.Also, if it

    39、were imperative for the bondline thickness to beknown for a hidden area (optically noncritical), it may bepossible to add a dye to the resin to give a distinction betweenit and the laminate.8.7 Other AnomaliesWhen comparing new transparenciesversus in-service transparencies, new transparencies are t

    40、ypi-cally clearer. As the transparency ages, certain areas tend to geta whitening effect. The whitening can be a result of environ-mental conditions such as UV exposure and thermal cycling.The whitening is an indication the transparency is weakened.Fig. 9 shows whitening at the top of an edge strip.

    41、9. Finding Interpretations9.1 Flaw SizeThe length of flaws is true as viewed in theprism. The prism skews the height of flaws. To determine theflaw height, the flaw size shall be compared to something ofknown height. For instance, if an edge block is in the prismview, the actual height of the edge b

    42、lock to the apparent heightgives the ratio required for determining the flaw height. Also,if the edge strip has a weave pattern of known height it mayalso be used. For bolt hole flaws, the flaw size relative to a bolthole size within the prism view shall be used for pass/failcriteria.10. Report10.1

    43、Suggested information for a report form.10.1.1 Background InformationInspectors name, inspec-tion date/time, P/N inspected, location of inspection, and areasinspected.FIG. 4 View of Bolt Holes in a Nylon/Acrylic Edge BlockFIG. 5 Cracks Stemming From a Bolt Hole (Side View)F210806410.1.2 Inspection S

    44、pecificsDelamination (Y/N), cracks(Y/N), voids (Y/N), dimensional tolerances (Y/N), bondlinethickness (Y/N), bolt hole flaws (Y/N), and other anomalies(list).10.1.3 Individual comments including any recommenda-tions and actions.11. Keywords11.1 bolt-hole inspection; canopy; cracks; delaminations;ins

    45、pection; prism; transparency; windscreenFIG. 6 Crack Stemming From a Bolt HoleFIG. 7 Air Bubble as Seen Through a PrismF2108065ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are

    46、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 years andif not re

    47、vised, 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 committee, which you

    48、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.FIG. 8 Resin Rich Area and Air Bubble as Seen Through a PrismFIG. 9 Whitening of an Edge Strip as Seen Through a PrismF2108066Thi

    49、s standard is copyrighted by ASTM International, 100 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).F2108067


    注意事项

    本文(ASTM F2108-2006 Standard Practice for Inspection of Transparent Parts by Prism《用棱镜对透光部分的检验用标准实施规程》.pdf)为本站会员(hopesteam270)主动上传,麦多课文档分享仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知麦多课文档分享(点击联系客服),我们立即给予删除!




    关于我们 - 网站声明 - 网站地图 - 资源地图 - 友情链接 - 网站客服 - 联系我们

    copyright@ 2008-2019 麦多课文库(www.mydoc123.com)网站版权所有
    备案/许可证编号:苏ICP备17064731号-1 

    收起
    展开