彈性鋼板應(yīng)力應(yīng)變實驗報告

《應(yīng)變片測彈性鋼板彎曲應(yīng)力》實驗報告院系:機(jī)電學(xué)院姓名：俞林學(xué)號：S310070077指導(dǎo)教師：馬洪文日期：2011年1月2日一、實驗?zāi)康模赫莆諟y量橋式電路的應(yīng)用，了解應(yīng)變片的應(yīng)變原理，了解彈性鋼板彎曲應(yīng)力變化規(guī)律，將不同厚度的彈性鋼板彎曲應(yīng)力變化規(guī)律進(jìn)行對比。二、實驗設(shè)備：電阻式應(yīng)變片，半橋式電路板，稱陀，彈性鋼板，HH1713雙路直流穩(wěn)壓電源，實驗機(jī)架(臺鉗與滑輪)，萬用表。三、實驗原理：不同受力方向的兩片應(yīng)變片接入電橋作為鄰邊，電橋輸出靈敏度提高，非線性得到改善。當(dāng)兩片應(yīng)變片阻值和應(yīng)變量相同時，其橋路輸出電壓Uo2=EKe/2。四、實驗內(nèi)容：制作半橋式電路板1).應(yīng)用Protel99SE軟件繪制電路圖。3).電路板的調(diào)試。

電阻應(yīng)變片的粘貼本實驗是在彈性上下個表面對稱位置貼一片電阻應(yīng)變片。1）.準(zhǔn)備工作：（1）測點表面打光為了使電阻應(yīng)變片能準(zhǔn)確地反映懸臂梁被測點的變形，必須使電阻應(yīng)變片和測點表面很好地結(jié)合，不發(fā)生任何滑移和阻礙變形的現(xiàn)象。為此，必須先用砂紙清除測點表面的油垢、鐵銹等，不允許有溝痕并使打磨條紋與電阻應(yīng)變片貼片方向成450,應(yīng)使表面粗糙度為Ra3?2左右，不應(yīng)過分粗糙，也不應(yīng)過分光滑。然后，用酒精棉球?qū)y點附近基本擦干凈。（2）（2）劃基準(zhǔn)線以測量點為中心用劃針劃十字線。（3）清潔表面用躡子夾取棉花球，沾酒精等清洗溶液仔細(xì)擦洗測點表面，以棉花球不見污物為止。2）.貼片：（1）取片就位待測點表面酒精晾干后，將502粘合劑均勻地涂在測點表面；用躡子將電阻應(yīng)變片取出,對準(zhǔn)事先劃好的十字基準(zhǔn)線貼在測點上。（2）擠壓在電阻應(yīng)變片表面蓋上吸水紙，輕輕擠出余膠，使貼好的電阻應(yīng)變片平直且下面沒有氣泡。（3）焊接導(dǎo)線用膠帶紙將電阻應(yīng)變片的引線和懸臂梁絕緣。將四根長度和粗細(xì)一樣的導(dǎo)線分別焊接在貼于彈性鋼板上、卜?表面的兩個電阻應(yīng)變片的四根引線上，并將導(dǎo)線固定在彈性鋼板上。應(yīng)變片貼中間的彈性鋼板應(yīng)變片貼在根部的彈性鋼板電源3.加載稱舵進(jìn)行應(yīng)力測量，并用萬用表記錄電壓數(shù)據(jù)如卜?:質(zhì)呈(kg)00.20.50.711.21.51.722.22.52.733.23.53.7誤差1電壓(mv)-84123439623823933111711891283134214011454149715221540157710.02電壓(mv)-6315144S64085195010991185128813451396145914921518155815727.83電壓(mv)-6314545963293996011211208127713421428146214991535155515688.6L=90mm,S=0?5mm（應(yīng)變片貼在中間）表1

平均電-70139.744S.7631.7837.7947.71112311941282713431408314583149615251551157238.8壓（mv）L=80mm,S=0?5mm（應(yīng)變片貼在中間）表2質(zhì)呈(kg)00.20.50.711.21.51.722.22.52.733.23.53.7誤羞1電壓(mv)-6721658879210511206135S14711574161516991723174917761807182119.92電壓(mv)-662115898171014115413531430153315S216491683173917721807183222.63電壓(mv)-6221759379710161174134914251514157616351688173017491797182612.7平均電壓（mv）-65214.7590802102711781353.3144215403159116611698173931765.71803.71826.31S.9L=80mm,S=0?5mm（應(yīng)變片貼在根部）表3質(zhì)M(kg)00.20.50.711.21.51.722.22.52.733.23.53.7誤差1電壓(mv)?5531S8(5810921284144516(5218021874196520922155225123102405243969.22電壓(mv)-283257459141234136816151748184S19382038212511012257233(5235521.73電壓(mv)-213027199381174135315521(5771S01190420002058210821(552256232953.3平均電壓（mv）-34.7315777.3918.31230.713S8.71(509.71742.318411935.72043.32112.721S6.7224423322374.352.0L=60mm,S=0?5mm（應(yīng)變片貼在中間）表4質(zhì)雖(kg)00.20.50.711.21.51.722.22.52.733.23.53.7誤差1電壓(mv)-721384255686998299299801030110111391162117711901202120411.32電壓(mv)-4S153421587734831927992104010801119113611601181119412016.73電壓(mv)-4215842959373982694099S105510901125114711731188120212077.5

平均電-54149.7425582.7724828.79329901041.7109031127.?114S.311701186.31199312048.7壓（mv）L=80mm,S=0?6mm（應(yīng)變片貼在中間）表5質(zhì)M(kg)00.20.50.711.21.51.722.22.52.733.23.53.7誤差1電壓(mv)-1101719532342757270379289497610921140123812581354142611.42電壓(mv)-9S26212324442572717S0291899410641118117412941371142613.33電壓(mv)-95282163274605697187969219781079114612311276135914058.6平均電壓（mv）-10123.7207.7324.7443571712.7796.7911982.7107S.31134.71214312761361.3141911.3L=90mm,S=0?6mm（應(yīng)變片貼在中間）表6質(zhì)M(kg)00.20.50.711.21.51.722.22.52.733.23.53.7誤差1電壓(mv)-11031217367528647811S911026110212361275135414281521156711.32電壓(mv)-105322483S0553639809S921053110312611301137414301486154210.53電壓(mv)-104322513S65456648049011037109311931302137514261486154111.9平均電壓（mv）-106.331.7238.7377.7542650808S94.7103S.71099312301292.71367.714281497.7155011.2L=80mm,S=0?6mm（應(yīng)變片貼在根部）表7（每次實驗間隔時間較長）質(zhì)雖(kg)00.20.50.711.21.51.722.22.52.733.23.53.7誤差1電壓(mv)■125-28103177305392497562677745839877944975105611075.22電壓(mv)■125-291021933033874895656727548318779509S7105410S05.23電壓(mv)」10-26103193307384495564674753847875952990106111015.6

平均電■12027.7102.7187.7305387.7493.7563.7674.3750.7839876.3948.79481057109653壓（mv）L=80mm,S=0?8mm（應(yīng)變片貼在中間）表8質(zhì)雖(kg)00.20.50.711.21.51.722.22.52.733.23.53.7課差1電壓(mv)■163-68211001742363173854465285826417287768428398.42電壓(mv)■127-59269S1752443143744595235916627307708468895.13電壓(mv)-121-63291051832493353844515186026547247778558906.8平均電壓（mv）■137-63.325.3101177.3243322381452523591.7652.3727.3774.3847.67890.676.9L=90nmi,S=0.8nun（應(yīng)變片貼在中間）表9質(zhì)雖(kg)00.20.50.711.21.51.722.22.52.733.23.53.7謀差1電壓(mv)-593214723130637151958166073882888496S10461115118S8.72電壓(mv)?394016324333640751457668174283690298110451145118910.43電壓(mv)-344415324431337351258566174S8349039771026110611708.0平均電壓（mv）-443&7154239.3318.3383.7515580.7667.3742.7832.78963975.3103911221182.39.1五、實驗數(shù)據(jù)及處理分析：實驗測量結(jié)果取平均值用MATLAB軟件進(jìn)行最小二乘擬合與上表對應(yīng)曲線圖如下:圖圖#12001000800GOO400200■2OOo0.512001000800GOO400200■2OOo0.51.53.52、實驗中的錯誤、原因及修改。錯誤一：在半橋式放大電路由于放人倍數(shù)選的過大使輸出的電壓只有15V左右。原因：由于選取的放人器的供電電壓是15V,放人器放人的輸出電壓不能超過自身的供電電壓。修改：更換電阻Rg由50歐改為500歐，由放大1000倍改為放大100倍。錯誤二：應(yīng)變片失效。原因：由于先貼應(yīng)變片，之后在彈性鋼板上打孔，打孔時的強(qiáng)烈振動使應(yīng)變片失效。修改：打孔后重新貼應(yīng)變片。錯誤三：測出當(dāng)彈性鋼板沒有形變時輸出電壓有壓差，并且很人。原因：應(yīng)變片引角與彈性鋼板相連，彈性鋼板有電阻，使測試點不等勢而有壓差。