有限元方法与分析课程结业论文-基于印刷机滚筒的模态分析.doc

有限元方法与分析课程结业论文论文题目 基于印刷机滚筒的模态分析 专 业 机械设计及理论 姓 名 学 号 联系方式 任课老师 印刷机滚筒的模态分析摘要：随着科技的进步，印刷技术也在日益提高，人们也在追逐高质量，高效益，品种多样化的印刷服务。印刷机的核心部件印刷机滚筒，其结构和动态性能对印刷工作特性有很大影响。运行中的振动问题直接影响到印刷的产品质量。本论文基于ansys软件对某型印刷机滚筒优化前后的模态分析。通过在pro/e软件下建立压印滚筒的实体模型，将实体模型导入有限元分析软件ansys中，用ansys对其进行模态分析，得到固有频率和振型。从动态特性上为静态优化结果提供了支持。根据不同尺寸的滚筒都做出模态分析的结果得出了一些结论，为后续印刷机滚筒的改装提供了坚实理论依据。关键词：印刷机滚筒；ansys；模态分析1 工作背景和工作原理滚筒是印刷机的核心部件，朝着轻量化的方向发展，其运动是旋转运动，印刷机高速运转时，其运动平稳性在很大程度上影响着印刷品质量，印刷时产生的重影、墨杆、网点扩大、墨色不均等故障都与滚筒的动态性能有关。造成印刷滚筒不平衡的原因很多，如滚筒质量分布不均匀、滚筒在长度方向上发生挠曲变形、压印力沿滚筒轴向分布不均匀，滚筒两端压印力大，中间部位压印力小所产生的振动等，因此对滚筒进行动态特性分析对提高印刷品质量有着重要的意义。2 理论分析并建立力学模型本实列以某四开胶印机压印滚筒为研究对象，建立有限元分析模型，运用有限元软件ansys对其进行模态分析，研究其振动特性。由于滚筒受外力包括重力、齿轮扭矩、印刷压力等。齿轮扭矩对滚筒挠曲变形产生的影响很小，可忽略不计，只考虑滚筒自身重力的作用。压印滚筒通过滑动轴承安装在墙板孔中，因此可以将滚筒看成两端约束的简支梁进行完全约束。2.1 模型的几何尺寸如下图给出了印刷机的结构简图，由图可以知道印刷机滚筒主要由滚筒和中心轴组成。表1给出了各部件的几何尺寸。表2 几何尺寸结构参数滚筒直径中心轴直径小孔直径连接轴直径侧面壁厚代号d1d2d3d4b1数值04m0.12m0.07m0.08m0.012m结构参数滚筒壁厚滚筒长度中心轴外段连接轴长度小孔距离中心代号b2ll1l2l3数值0.015m2.4m0.1m0.08m0.1m图1 印刷机滚筒的三视图图2 印刷机滚筒的三维图2.2 单元的选择及材料常数本实例采用三维的八节点solid185单元来模拟整个印刷机滚筒。滚筒的材料为45号刚，其弹性模量为2.1e11pa,泊松比为0.3，密度为7850kg/m3.3 有限元程序开发和参数优化3.1 建立模型用pro/e软件按照如表1的尺寸以及图1的三视图模型建立印刷机滚筒模型。将文件保存为iges文件。如图2所示。打开ansys软件，通过file文件import到入用pro/e建立的iges文件，即完成模型的建立。32 定义单元和属性模型生成以后，接着在前处理的下拉菜单中进行定义单元类型和材料类型，进行任何有限元分析都必须选择合适的单元类型，单元类型决定附加的自由度，对于印刷机滚筒，主要是研究其模态分析，在整个过程中更关心的是其振动特性，因此选用实体单元solid185进行结构离散。并且设置弹性模量（2.1e11pa）、泊松比（0.3）和密度（7850kg/m3）。33 网络划分 网格划分的过程就是结构离散化的过程，通常划分的单元越多越密集，就越能反映实际结构状况，计算精度越高，计算工作量越大，计算时间增长。为兼顾计算精度和计算效率，采用自动划分的方法进行网格划分。利用软件智能自动给滚筒进行划分网格，网格精度取smart size 5。网格划分结果如图3所示：图3 印刷机滚筒的网络划分后模型3.4 进行静力求解 由于压印滚筒所受外力有多钟。其中齿轮扭矩对滚筒挠度变形产生的影响很小，可以忽略不计，因而只考虑滚筒自身重力的作用。压印滚筒通过滑动轴承安装在墙板孔中，因而可以将滚筒看出两端约束的简支梁进行完全约束。因而将求解类型设置成静态求解，给连接轴的两端施加约束，并对滚筒施加重力载荷进而求解。3.5 进行模态求解 通过设置求解类型为模态分析，并设置模态分析的一些参数，如设置模态提取数为5等并进行求解。36 后处理查看滚筒的固有频率，如图4所示，并提取第每阶固有频率的振型如图5、图6、图7、图8、图9所示。 图4 印刷机滚筒固有频率图4 印刷机滚筒第1阶模态振 图5 印刷机滚筒第2阶模态振型 图6 印刷机滚筒第3阶模态振型 图7 印刷机滚筒第4阶模态振型图8 印刷机滚筒第5阶模态振型 修改印刷机滚筒的参数：b2=0.013m;b1=0.05m;d2=0.12m。按上述方法重新做一遍便可得出印刷机滚筒的固有频率和5阶振型。如图10、图11、图12、图13、图14、图15所示。图10 印刷机滚筒固有频率图11 印刷机滚筒第1阶模态振型 图12 印刷机滚筒第2阶模态振型图13 印刷机滚筒第3阶模态振型 图14 印刷机滚筒第4阶模态振型图15 印刷机滚筒第5阶模态振型3.7 结果分析综上分析，滚筒的尺寸不一样时，其固有频率也有差异。但两种不同尺寸的滚筒的振型没有明显变化。从上述模态振型图可以看出，滚筒在前3阶固有频率下，振型主要是以中间梁的弯曲变形为主。而在后边两阶是以中间梁和外筒的弯曲变形。从上述两种不同尺寸的模态振型图的结果对比可以得出，在修改滚筒的一些参数时，共振影响不大。但是从二者对比可以看出适当减小滚筒厚度和内梁直径并增加侧壁厚度的厚度是可行的。4 结语1） 使用ansys有限元分析软件解决了传统的模态分析问题，作为一种新的设计手段，从动态特性上为静态优化结果提供了支持。2） 验证了适当减小滚筒厚度和内梁直径并增加侧壁的质量是可行的。参考文献：1 张洪才，有限元分析ansys13.0从入门到实战，机械工业出版社，2012年4月，517页。2张立新，ansys7.0基础教程，机械工业出版社，2004年3月，244页。3祝磊，ansys7.0入门与提高，清华大学出版社，2004年7月，379页4杜亚男，印刷机的模态分析，包装工程，510006,2011年8月，4页5杨家华，印刷机振动测试与分析，北京工业大学学报，第30卷第1期，2004年5月，4页。附件1（命令流）/nopr ! suppress printing of undo process /pmacro ! echo following commands to log finish ! make sure we are at begin level /clear,nostart ! clear model since no save found ! we suggest you remove this line and the following startup lines /input,menust,tmp,1 /gra,power /gst,on /plo,info,3 /gro,curl,on/cplane,1 /replot,resize wpstyle,0/filname,5,0/title,5/aux15 !* ioptn,iges,smooth ioptn,merge,yes ioptn,solid,yes ioptn,small,yes ioptn,gtoler, defa igesin,123456,igs,.proeyouxianyuanzuoyevplot !* finish /prep7 !* et,1,solid185 !* !* mptemp, mptemp,1,0 mpdata,ex,1,2.1e11 mpdata,prxy,1,0.288mptemp, mptemp,1,0 mpdata,dens,1,7850 smrt,6 smrt,5 mshape,1,3d mshkey,0!* cm,_y,volu vsel, , , , 1 cm,_y1,volu chkmsh,volu cmsel,s,_y !* vmesh,_y1 !* cmdele,_y cmdele,_y1 cmdele,_y2 !* finish /sol!* antype,0/user, 1 /view, 1, 0.692111943844 , 0.321103168199 , 0.646431599290/ang, 1, 12.1606464575 /replo /view, 1, 0.470567854088 , 0.427919802871 , 0.771654415531/ang, 1, 6.04288451640 /replo /view, 1, 0.654364861158 , -0.392970517756 , 0.646050153360/ang, 1, -4.27717159610 /replo /view, 1, 0.550758399173 , -0.653513216609 , 0.519216391747/ang, 1, -4.95954011275 /replo flst,2,1,5,orde,1 fitem,2,68 !* /go da,p51x,ux, flst,2,1,5,orde,1 fitem,2,68 !* /go da,p51x,uy, flst,2,1,5,orde,1 fitem,2,68 !* /go da,p51x,uz, /view, 1, -0.544697275514 , -0.616435687599 , 0.568605241887/ang, 1, 60.6247141398 /replo /view, 1, -0.893495573342 , -0.412684834613 , 0.177078761285/ang, 1, 79.8375474749 /replo /view, 1, -0.776181112388 , -0.579310317946 , -0.248882374413/ang, 1, 97.1839152481 /replo /view, 1, -0.534268681398 , -0.767699054022 , -0.353829250530/ang, 1, 107.950137149 /replo /view, 1, -0.730821237300 , -0.585440629261 , -0.350941004618/ang, 1, 102.572268236 /replo flst,2,1,5,orde,1 fitem,2,76 !* /go da,p51x,ux, /view, 1, -0.512612053737 , -0.754351719334 , -0.410100433920/ang, 1, 111.257524777 /replo flst,2,1,5,orde,1 fitem,2,76 !* /go da,p51x,uy, flst,2,1,5,orde,1 fitem,2,76 !* /go da,p51x,uz, acel,0,9.8,0, /replot,resize /status,solusolve !* !* !* finish /solution antype,2!* !* !* modopt,lanb,5 eqslv,spar mxpand,5, , ,0 lumpm,0 pstres,1!* modopt,lanb,5,0,0, ,off /status,solusolve finish /post1 set,listset,list,999set, , ,1 !* /efacet,1 plnsol, u,sum, 0,1.0/foc, 1, 1152.62859868 , 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/dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,1.37174211248,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /zoom,1,scrn,0.373066,-0.056107,0.248798,-0.072137 /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /view, 1, -0.303974895465 , -0.934999895344 , 0.182686777393/ang, 1, 47.0222603184 /replo /foc, 1, -2993.07785030 , -6935.96177116 , 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, -0.396770231349/ang, 1, 129.859269893 /replo /view, 1, -0.546763694962 , -0.732440476302 , -0.405685112552/ang, 1, 134.842329241 /replo /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /view, 1, -0.339831015383 , -0.795054611276 , -0.502397299030/ang, 1, 149.422222637 /replo set,list,999set, , ,3 !* /efacet,1 plnsol, u,sum, 0,1.0/dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /dist,1,0.729,1 /rep,fast /auto,1 /rep,fast /zoom,1,rect,0.597549,-0.128244 ,1.00643023606 ,-0.108206101956 /auto,1 /rep,fast /user, 1 /view, 1, -0.895309168630 , -0.355273186869 , -0.268705145576/ang, 1, 124.386127380 /replo /view, 1, -0.823349010166 , 0.488252689613 , 0.289319405751/ang, 1, 127.185337877 /replo /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast set,list,999set, , ,4 !* /efacet,1 plnsol, u,sum, 0,1.0/zoom,1,rect,0.533411,-0.284542 ,-0.324436864408 ,-0.0200381670289 /auto,1 /rep,fast /user, 1 /view, 1, -0.345900936836 , -0.839273387561 , -0.419491028305/ang, 1, 128.854215406 /replo /view, 1, -0.369195661989 , -0.913121218386 , -0.172928319549/ang, 1, 106.438347345 /replo /zoom,1,rect,0.216729,-0.396756 ,0.184659887881 ,-0.480916008694/view, 1, -0.370985246955 , -0.914279270672 , -0.162675633582/ang, 1, 105.140195013 /replo /auto,1 /rep,fast /user, 1 /view, 1, -0.174594752148 , -0.953904628332 , 0.244095539840/ang, 1, 30.3510943299 /replo /view, 1, -0.111308972024 , -0.815663720400 , 0.567717366276/ang, 1, 8.12945732606 /replo /zoom,1,rect,0.252807,-0.380725 ,0.224746246329 ,-0.60916027768 /auto,1 /rep,fast /user, 1 /view, 1, 0.892777808621e-01, -0.690107440169 , 0.718179085513/ang, 1, -6.20271418698 /replo /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /foc, 1, 1140.15836729 , 82.5399219788 , 20.7837828703/replo /dist, 1, 1041.82895488 /ang, 1, -1.40271418698 /replo /dist, 1, 1041.82895488 /ang, 1, -1.40271418698 /lig, 1,1, 1.000, 0.00000000000 , 0.00000000000 , 0.00000000000 , 0.00000000000 /replo /zoom,1,rect,0.385092,0.428817 ,0.521385298844 ,0.364694639927 /auto,1 /rep,fast /user, 1 /dist, 1, 1205.80674147 /ang, 1, 4.89728581302 /replo /zoom,1,rect,0.256815,0.460878 ,0.332979414138 ,0.428816774419 /auto,1 /rep,fast /user, 1 /view, 1, 0.570707897491e-01, 0.929958051205 , 0.363209234405/ang, 1, -140.167003993 /replo /dist, 1, 1144.08184619 /ang, 1, -159.667003993 /replo /dist, 1, 1016.20167081 /ang, 1, -167.467003993 /replo /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /dist, 1, 1043.87392729 /ang, 1, -169.267003993 /replo /dist, 1, 955.458324640 /ang, 1, -170.167003993 /replo /dist, 1, 1277.91643155 /ang, 1, -163.867003993 /replo /dist, 1, 1506.20525192 /ang, 1, -151.267003993 /replo /dist, 1, 1645.58552799 /ang, 1, -21.9670039930 /replo /view, 1, -0.491408888816e-01, 0.695819468809 , 0.716533627868/ang, 1, -32.2511861613 /replo /dist, 1, 1494.35005857 /ang, 1, -5.85118616130 /replo /dist, 1, 1703.80714444 /ang, 1, -32.2511861613 /replo /dist,1,1.08222638492,1 /rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,1.08222638492,1 /rep,fast /dist,1,1.08222638492,1 /rep,fast /view, 1, -0.180802016774 , 0.376828330687 , 0.908466311936/ang, 1, -35.9656955071 /replo /view, 1, -0.345864090521 , -0.121796779243 , 0.930345943966/ang, 1, -36.7744425564 /replo /view, 1, -0.323905437111 , -0.408219124805 , 0.853488379507/ang, 1, -36.4670236713 /replo /dist,1,0.924021086472,1/rep,fast /view, 1, -0.297045468730 , -0.284462352091 , 0.911507081569/ang, 1, -37.5057161791 /replo set,list,999set, , ,5 !* /efacet,1 plnsol, u,sum, 0,1.0/view, 1, -0.433986630556 , -0.810664783986 , 0.393037164278/ang, 1, -17.1999218344 /replo /view, 1, 0.174241070646 , 0.776760430952 , -0.605213418727/ang, 1, 29.1623586916 /replo /view, 1, 0.256029986462 , 0.840102756574 , -0.478200799277/ang, 1, 19.3032907387 /replo )/gop ! resume printing after undo process )! we suggest a save at this point /nopr ! suppress printing of undo process /pmacro ! echo following commands to log finish ! make sure we are at begin level /clear,nostart ! clear model since no save found ! we suggest you remove this line and the following startup lines /input,menust,tmp,1 /gra,power /gst,on /plo,info,3 /gro,curl,on/cplane,1 /replot,resize wpstyle,0/replot,resize /filname,6,0/title,6/filname,7,0/title,7/aux15 !* ioptn,iges,smooth ioptn,merge,yes ioptn,solid,yes ioptn,small,yes ioptn,gtoler, defa igesin,xinmoxing,igs,.proeyouxianyuanzuoye vplot !* finish /prep7 !* et,1,solid185 !* !* mptemp, mptemp,1,0 mpdata,ex,1,2.1e11 mpdata,prxy,1,0.288mptemp, mptemp,1,0 mpdata,dens,1,7850 smrt,6 smrt,5 mshape,1,3d mshkey,0!* cm,_y,volu vsel, , , , 1 cm,_y1,volu chkmsh,volu cmsel,s,_y !* vmesh,_y1 !* cmdele,_y cmdele,_y1 cmdele,_y2 !* finish /sol!* antype,0/user, 1 /view, 1, -0.422466028597 , 0.775588962245e-02, 0.906345574744/ang, 1, -13.4566960390 /replo /view, 1, -0.550830938885 , -0.156902990237 , 0.819735767441/ang, 1, -12.6393844723 /replo /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast /dist,1,0.924021086472,1/rep,fast