abaqus有限元分析報告開裂梁

Abaqus梁的開裂模擬計算報告問題描述利用ABAQUS1.1Brenaetal.（2003）得到梁的基本數(shù)據(jù)：圖1.1Brenaetal.（2003）中梁C尺寸幾何尺寸：跨度3000mm，截面寬203mm，高406mm的鋼筋混凝土梁由文獻Chenetal.2011得材料特性：混凝土：抗壓強度c=35.1MP，抗拉強度t=2.721MP，泊松比=0.Ec=28020MPa；鋼筋：彈性模量為Ec=200GPa，屈服強度fys=fyc=440MPa，fyv=596MPa混凝土墊塊：彈性模量為Ec=28020MPa，泊松比ν=0.2建模過程Part打開ABAQUS使用 功能模塊彈出窗口CreatePar參數(shù)為點擊ContinueSketch二維繪圖區(qū)。由于該梁關(guān)于Y軸對稱，建模的時候取沿X象。使用 并按下下方示區(qū)的Done，完成草圖。2.1beam部件二維幾何模型相同的方法建立混凝土墊塊：圖2.2plate部件二維幾何模型所選用的點有(0,0),(40,0),(40,10),(0,10)受壓區(qū)鋼筋：在選擇鋼筋的basefeature的時候選擇wire，即線模型。圖2.3compressionbar部件二維幾何模型選取的點(0,0),(1575,0)受拉區(qū)鋼筋：選取的點(0,0),(1575,0)箍筋：

2.4tensionbar部件二維幾何模型2.5stirrup部件二維幾何模型選取的點為(0,0),(0,330)。PropertyModule中選擇property，然后選擇功能模塊對不同的材料進行賦值，下面是各種材料輸入時候的數(shù)據(jù)：①混凝土本構(gòu)關(guān)系：（該模型的尺寸單位為）在彈出的對話框中命名為bea，在Mechanical選項中點擊Elastic，在Modulus28020000000，Poisson’sRatio0.2；類似的方法找到ConcreteDamaged，按混凝土結(jié)構(gòu)設(shè)計規(guī)范對受壓取點8個，受拉取點個。下面是計算過程：由規(guī)范中附錄C中C2混凝土本構(gòu)關(guān)系：應(yīng)變曲線公式：(1d)Et c ，所用參數(shù)可以參考規(guī)范（混凝土結(jié)構(gòu)設(shè)計規(guī)范GB50010-2010）應(yīng)變曲線公式：(1d)Ec c ，所用參數(shù)可以參考規(guī)范以及塑性應(yīng)變與總應(yīng)變的關(guān)系：el

，其中 pl el E以及塑性應(yīng)變與總應(yīng)變的關(guān)系：el

，cr

與上式相同借助matlab0.00050.0010.002、0.003、0.004、0.005、0.008得對應(yīng)應(yīng)力為23171225.88、35072364.432320980.31、17763125.96、13340141.18、10334750.06、5892086.123；開裂應(yīng)變分別取、0.001、0.003、0.005、0.008、0.01、0.05得對應(yīng)應(yīng)力2721000、2648625.968、875761.085、511922.937、334706.391、50489.31、16333.482。由于水平限制，算得的受拉損傷因子未能通過abaqus的算前檢測，這里沒有輸入。模（該模型單元尺寸為）Elastic候按照文獻Finite-ElementModelingofIntermediateCrackDebondinginFRP-PlatedRCBeams，G.M.Chen中的公式：單軸受壓：

，所用參數(shù)可見于引用的文獻；1[( /)2](/p p

)(/)2p p受壓的時候為了尋找輸入塑性應(yīng)變的起始點，令abaqus中提供的應(yīng)力--應(yīng)變輸入方式的名義值與真實值關(guān)系公式為0，有：ln(1

nom

(1 )) nom nom 0Enom

1[(

/) nom

/)(

nom

/)2解之得：

nom

22.76652048MPa，

nom

0.00081284，ln

0。nom0.000812840.000283個點。在輸入到abaqus前使用公式plln

ln(1

)nom

nom

(1E

)nomtrue

nom

(1

)nom進行轉(zhuǎn)換，輸入的具體值可見附錄。 ww (c t) wt單軸受拉：ttf

[1(c 1w

)3

2w (1c3)e(cwcr21wcr2

)，所用參數(shù)可見于引用文獻；t cr cr由于hc（上面提到的文獻中也命名為平面四節(jié)點單元的特征裂縫長度2e，其中ehc14mm。在清華江見鯨或者.ROTS撰寫的文獻中都能找到其他單元類型的hce式，這里提到的hc也可稱為Lcr，這提供了把本文中的開裂位移轉(zhuǎn)化為開裂應(yīng)變的方法：wt

Lcr crwt10,280.0012130.00653個點。把位移轉(zhuǎn)換成應(yīng)變以后，同樣地，使用名義值--真實值的轉(zhuǎn)換公式得到數(shù)據(jù)，具體數(shù)值可見于附錄。由于水平問題，算得的受拉損傷因子未能通過abaqus的算前檢測，這里沒有輸入。模型三：該模型使用的尺寸單位為mm，受壓時的取值只需在模型二的取值基礎(chǔ)上進行單位換算即可。本構(gòu)關(guān)系的輸入方式為應(yīng)力--位移的方法，在輸入類型中選擇Displacement單軸受拉：對wt進行離散，取等步長0.0012，共51個點。這里還進行了受拉損傷因子wdtd

t ，具體數(shù)據(jù)可見附錄。t [wt②鋼筋本構(gòu)關(guān)系：

(hc

)/E]t c類似的，把鋼筋的楊氏模量輸入到Elastic中，三個模型的受拉受壓鋼筋都是在Plastic真實值得方法，取得兩個點：屈服強度440MPa0；448.8MPa0.02596MPa0。③墊塊的本構(gòu)關(guān)系：的本構(gòu)關(guān)系作為其材料屬性。建立完本構(gòu)關(guān)系后需對混凝土等截面屬性進行賦值，點擊 ，彈出CreateSection對Categorymaterialbeam，thickness203mm設(shè)為beaType設(shè)為trus，如受拉鋼筋，由文獻得直徑為16m，面積為200.9（m，由于4029.5mm7mm計算。然后再同一個環(huán)境欄中使用 ，提示區(qū)要求用戶選擇賦予截面的部件，分別對上創(chuàng)建過的部件賦予材料屬性，完成操作。Assembly進入Assembly模塊，如圖2.6裝配完畢的模型所示進行裝配。圖2.6裝配完畢的模型墊塊的位置和鋼筋的布置嚴格按照文獻Finite-ElementModelingofIntermediateCrackDebondinginFRP-PlatedRC.M.Chen進行。為了后期布置網(wǎng)格時候的方便，使用對所有鋼筋進行組合，然后對組合后的鋼筋在模型樹中的instanceindependenStep在環(huán)境欄的Module列表中進入Step模塊。點擊 如下圖進行設(shè)置：2.7Step-1的Basic選項圖2.8Step-1的Incrementation選項圖中，Minimum不需要設(shè)置很小，Maximumnumberofincrements當(dāng)模型真的不收斂的時候這兩項的影響比較小Maximun的設(shè)置回影響到Job中計算時的總增量步數(shù)目。Interaction圖2.9約束管理器圖2.10加載點coupling約束2.11鋼筋與混凝土的embededregion約束圖2.12墊塊與混凝土梁的tie約束按照上述圖示的對象設(shè)置相關(guān)約束，完畢后結(jié)束該操作。Load如下圖所示，在環(huán)境欄的Module列表中選擇Load模塊，進行荷載與邊界條件的定義。①定義邊界條件點擊 ，彈出對話框createboundarycondition，step選擇initial，category選擇forselectedstep選擇對稱軸，邊界類型選擇XSYMM（鎖定轉(zhuǎn)角是因為對稱的位置需要承受彎矩的邊界條件，step選擇initial，category選擇mechanical，typesforselectedstep選擇displacement/rotation，點擊continue，然后選擇左下角墊塊下部的最左邊角點（這里選擇下部的邊上一點就可以，具體的位置對模擬影響不大）上約束類型限制U2。②施加荷載

圖2.13梁的約束示意圖這里采用的是位移加載法，設(shè)置見圖2.14。圖2.14位移和在的施加是施加在Y單位為米-0.02（單位為米-3（單位為毫米）Mesh首先使用工具 對鋼筋單元默認的beam單元更改為truss單元。然后使用 對整個模型進行撒種，撒種之前可以使用行網(wǎng)格劃分，效果如下：

控制網(wǎng)格類型。撒種以后點擊

對整個模型進圖2.15網(wǎng)格單元30mm×30mm效果圖（模型一）圖2.16網(wǎng)格單元10mm×10mm效果圖（模型二、模型三）計算結(jié)果Job在環(huán)境欄的Module列表中選擇Job功能模塊進行作業(yè)提交①創(chuàng)建分析作業(yè)點擊工具 彈出createjob對話框source分別選擇模型Model1模型一Model-lcr（模型二Model-m（模型三，建立的JobNam，對應(yīng)為num-11-1完成作業(yè)生成。②提交分析點擊工具 （JobManage，分別對三個模型submi，可以再status中看到經(jīng)歷submitted--running--completed的過程。Visualization①在住菜單JobManager，中點擊Results，如下圖方法查看裂縫效果圖：該界面下編號①中可更改為L（對數(shù)應(yīng)變?nèi)氲脑茍D參數(shù)進行設(shè)置；③則為具體輸出的模擬結(jié)果曲線圖等的操作工具。3.2能是導(dǎo)致裂縫出現(xiàn)的數(shù)目比較少的原因；模型二在加載處左端的裂縫都基本能沿450發(fā)展，3mm，裂縫出現(xiàn)，但并不明顯，可見于圖3.，圖3.5在元模型的基礎(chǔ)上修改粘結(jié)系數(shù)為0.000（原為0，裂縫出現(xiàn)，但裂縫開展與圖3.1visualization模塊使用了的工具位置示意圖圖3.2模型一的裂縫模擬圖圖3.3模型二的裂縫模擬圖圖3.4模型三不帶粘性系數(shù)的裂縫模擬圖圖3.5模型三粘結(jié)系數(shù)為0.0005的裂縫模擬圖在以后的模擬中有待研究。②荷載--位移曲線3.1CreateXYODBfieldoutpucontinuposition選擇uniquenodaRF與Uselection選項中拾取參考點，選中以后點擊plot位移曲線；再次點CreateXYoperateonxycombine操作對輸出的數(shù)據(jù)進行重新布置，下方xydata欄中有剛才輸出的數(shù)據(jù)，雙擊的一個數(shù)據(jù)會成為x軸上的數(shù)據(jù)，第二個則為y軸上的數(shù)據(jù)，結(jié)束后點擊plotexpression，這一步更好的做法是在模型樹中找到的繪制。下面是excel表示的曲線圖：

，把對應(yīng)的數(shù)據(jù)復(fù)制到excel中進行表哥③受拉區(qū)混凝土應(yīng)力應(yīng)變曲線類④受壓區(qū)混凝土應(yīng)力應(yīng)變曲線類⑤受拉區(qū)鋼筋應(yīng)力--應(yīng)變曲線類似上一小節(jié)的方法得到其曲線圖：附錄①模型二混凝土本構(gòu)取值：*Material,name=beam*Elastic2.802e+10,0.2*ConcreteDamagedPlasticity35., 0.1, 1.16,0.667, 0.*ConcreteCompressionHardening2.27665e+07, 0.2.70001e+07,4.87e-053.02955e+07,0.0001313.26542e+07,0.0002463.41623e+07,0.0003923.49521e+07,0.0005643.51697e+07,0.0007563.49536e+07,0.0009633.44232e+07, 0.001183.36758e+07,3.27869e+07,3.18134e+07,

0.001410.001640.001873.0797e+07, 0.002112.97674e+07,2.87453e+07,2.77447e+07,2.67749e+07,2.58415e+07,2.49476e+07,

0.002340.002580.002820.003050.003280.003512.40945e+07, 0.003742.32824e+07,2.25106e+07,2.17779e+07,2.10827e+07,2.04233e+07,1.97978e+07,1.92044e+07,1.86412e+07,1.81065e+07,1.75984e+07,

0.003970.00420.004420.004650.004870.005090.005310.005530.005750.005961.71153e+07, 0.006181.66558e+07,1.62183e+07,1.58014e+07,

0.006390.006610.006821.5404e+07, 0.007031.50247e+07,1.46626e+07,1.43165e+07,1.39854e+07,1.36686e+07,1.33652e+07,

0.007250.007460.007670.007880.008090.00831.30743e+07,0.008511.27953e+07,0.008711.25275e+07,0.008921.22702e+07,0.009131.2023e+07,0.009341.17852e+07,0.009541.15563e+07,0.009751.13359e+07,0.009951.11235e+07,0.01021.09187e+07,0.01041.07212e+07,0.01061.05305e+07,0.01081.03463e+07, 0.0111.01683e+07,0.01129.99628e+06,0.01149.82985e+06,0.01169.66877e+06,0.01189.51282e+06, 0.0129.36174e+06,0.01229.21532e+06,0.01249.07336e+06,0.01268.93565e+06,0.01288.80203e+06, 0.0138.6723e+06,0.01328.5463e+06,0.01348.42389e+06,0.01368.30491e+06,0.01388.18923e+06, 0.0148.0767e+06,0.01427.96721e+06,0.01447.86064e+06,0.01467.75687e+06,0.01487.6558e+06, 0.0157.55732e+06,0.01527.46134e+06,0.01547.36777e+06,0.01567.27651e+06,0.01587.18748e+06, 0.0167.10061e+06,0.01627.01582e+06,0.01646.93303e+06,0.01666.85218e+06,0.0168*ConcreteTensionStiffening2.72126e+06, 0.2.7069e+06,8.55431e-062.69288e+06,1.71134e-052.67893e+06,2.56725e-052.66504e+06,3.42317e-052.65124e+06,4.2791e-052.6375e+06,5.13503e-052.62384e+06,5.99096e-052.61024e+06,6.8469e-052.59672e+06,7.70285e-052.58327e+06,8.5588e-052.45263e+06,0.0001711862.32886e+06,0.0002567872.21176e+06,0.0003423912.10108e+06,0.0004279981.99659e+06,0.0005136051.89805e+06,0.0005992131.80521e+06,0.0006848211.71782e+06,0.0007704281.63563e+06,0.0008560321.5584e+06,0.0009416351.48589e+06,0.001027241.41785e+06,0.001112831.35405e+06,0.001198421.29426e+06,0.001284011.23826e+06, 0.00136961.18584e+06, 0.001455181.13679e+06, 0.001540751.09091e+06, 0.001626321.04799e+06, 0.001711881.00787e+06, 0.00179743970351., 0.00188298935276., 0.00196853902480., 0.00205406871807., 0.00213959843113., 0.00222512816256., 0.00231063791107., 0.00239614767539., 0.00248164669549., 0.00290904596170., 0.00333626538552., 0.0037633490607., 0.00419016448335., 0.00461685409265., 0.00504336371992., 0.00546971335828., 0.00589588300538., 0.00632189266152., 0.00674773232837., 0.00717339200804., 0.00759888170262., 0.0080242②模型三混凝土本構(gòu)取值：*Material,name=beam*Elastic28020.,0.2*ConcreteDamagedPlasticity35., 0.1, 1.16,0.667, *ConcreteCompressionHardening22.7665, 0.27.0001,4.87e-0530.2955,0.00013132.6542,0.00024634.1623,0.00039235.,0.00056435.2,0.00075634.9536,0.00096334.4232, 0.0011833.6758, 0.0014132.7869, 0.0016431.8134, 0.0018730.797, 0.0021129.7674, 0.0023428.7453, 0.0025827.7447, 0.0028226.7749, 0.0030525.8415, 0.0032824.9476, 0.0035124.0945, 0.0037423.2824, 0.0039722.5106, 0.004221.7779, 0.0044221.0827, 0.0046520.4233, 0.0048719.7978, 0.0050919.2044, 0.0053118.6412, 0.0055318.1065, 0.0057517.5984, 0.0059617.1153, 0.0061816.6558, 0.0063916.2183, 0.0066115.8014, 0.0068215.404, 0.0070315.0247, 0.0072514.6626, 0.0074614.3165, 0.0076713.9854, 0.0078813.6686, 0.0080913.3652, 0.008313.0743, 0.0085112.7953, 0.0087112.5275, 0.0089212.2702, 0.0091312.023, 0.0093411.7852, 0.0095411.5563, 0.0097511.3359, 0.0099511.1235, 0.010210.9187, 0.010410.7212, 0.010610.5305, 0.010810.3463, 0.01110.1683, 0.01129.99628, 0.01149.82985, 0.01169.66877, 0.01189.51282, 0.0129.36174, 0.01229.21532, 0.01249.07336, 0.01268.93565, 0.01288.80203, 0.0138.6723, 0.01328.5463, 0.01348.42389, 0.01368.30491, 0.01388.18923, 0.0148.0767, 0.01427.96721, 0.01447.86064, 0.01467.75687, 0.01487.6558, 0.0157.55732, 0.01527.46134, 0.01547.36777, 0.01567.27651, 0.01587.18748, 0.0167.10061, 0.01627.01582, 0.01646.93303, 0.01666.85218, 0.0168*ConcreteTensionStiffening,type=DISPLACEMENT2.721, 0.2.58017,0.00122.44675,0.00242.32051,0.00362.20119,0.00482.08855, 0.0061.98232,0.00721.88224,0.00841.78805,0.00961.69947,0.01081.61624, 0.0121.5381,0.01321.46479,0.01441.39607,0.01561.33168,0.01681.27138, 0.0181.21494,0.01921.16214,0.02041.11276,0.02161.06659,0.02281.02343, 0.0240.983093,0.02520.945393,0.02640.910156,0.02760.877216,0.02880.846415, 0.030.817603,0.03120.79064,0.03240.76539,0.03360.741727,0.03480.719533, 0.0360.698696,0.03720.679109,0.03840.660676,0.03960.643302,0.04080.62690