算例二:如图所示转子,转子具体尺寸见程序中的输入参数,转子弹性模量为2.095e11Pa,转子材料密度为7.85e3kg/m3,转子支承刚度 5.0e7 N/m。
计算程序如下:
- clc
- clear all;
- Nshaft=5; %轴段数量;
- %%
- RotorE = 2.095e11; %转子弹性模量;
- RotorM = 7.85e3; %转子材料密度
- ShaftL = [0.55,0.45,0.45,0.55,0.5]; %各轴段长度
- ShaftDI = ones(1,Nshaft)*0.1;ShaftDI(2)=0.15;ShaftDI(3)=0.15; %各轴段外径
- ShaftDO = ones(1,Nshaft)*0.0; %各轴段内径;
- LocationF=[1,5]; %支承所在节点编号;
- SPtype= 2; %支承类型选择, 1 -- 刚性支承, 2 -- 弹性支承;
- LocationF=[1,5]; %支承所在节点编号;
- SPstiffness=[5.0e7 5.0e7]; %支承刚度,SPtype = 1时,无需进行任何设置;
- %%
- addtionN = [2,3,4,6]; %附加轮盘编号
- addtionM = [144.1157,288.2313,144.1157,144.1157]; %附加轮盘质量
- addtionJ = [4.7933,18.4648,4.7933,4.7933]; %附加轮盘转动惯量
- %%
- CSN = 5;
- CriticalSpeeds=Chinavib_CriticalSpeeds(Nshaft,RotorE,RotorM,ShaftL,ShaftDI,ShaftDO,SPtype,LocationF,SPstiffness,addtionN,addtionM,addtionJ,CSN)
复制代码
计算结果如下:
CriticalSpeeds =
1.0e+004 *
0.1314
0.2050
0.4457
0.8980
1.2281
改变分段方式如下:
计算程序如下:- clc
- clear all;
- Nshaft=9; %轴段数量;
- %%
- RotorE = 2.095e11; %转子弹性模量;
- RotorM = 7.85e3; %转子材料密度
- ShaftL = [0.5,0.1,0.4,0.1,0.4,0.1,0.5,0.4,0.1]; %各轴段长度
- ShaftDI = ones(1,Nshaft)*0.1;ShaftDI(2)=0.15;ShaftDI(3)=0.15; %各轴段外径
- ShaftDI(4)=0.15;ShaftDI(5)=0.15;ShaftDI(6)=0.15;
- ShaftDO = ones(1,Nshaft)*0.0; %各轴段内径;
- SPtype= 2; %支承类型选择, 1 -- 刚性支承, 2 -- 弹性支承;
- LocationF=[1,8]; %支承所在节点编号;
- SPstiffness=[5.0e7 5.0e7]; %支承刚度,SPtype = 1时,无需进行任何设置;
- %%
- addtionN = [2,3,4,5,6,7,9,10]; %附加轮盘编号
- addtionM = [70.1311,70.1311,144.1157,144.1157,70.1311,70.1311,70.1311,70.1311]; %附加轮盘质量
- addtionJ = [2.3888,2.3888,9.2324,9.2324,2.3888,2.3888,2.3888,2.3888]; %附加轮盘转动惯量
- %%
- CSN = 5;
- CriticalSpeeds=Chinavib_CriticalSpeeds(Nshaft,RotorE,RotorM,ShaftL,ShaftDI,ShaftDO,SPtype,LocationF,SPstiffness,addtionN,addtionM,addtionJ,CSN)
复制代码 计算结果如下:
CriticalSpeeds =
1.0e+004 *
0.1378
0.2166
0.4518
0.9169
1.1840
两种不同分段形式所得到的结果不同,主要是因为分段时考虑轴段刚度不一致造成的
在第一种分段模式中,在2节点处轴段左侧轴段直径为0.1m,第4节点处右侧的轴段直径为0.1m
而第二种分段模式中,上述两个位置轴段的直径为0.15m,因此低阶临界转速的计算结果要略高一点
实际计算时,如果要获得比较准确的结果,需要考虑轮盘对转子临界转速的影响,其考虑办法可以参考西安交通大学编写的《透平零件结构和强度计算》一书中的相关内容进行修正。
对第二种分段模式节点进行加密,如图
计算程序如下:- clc
- clear all;
- Nshaft=14; %轴段数量;
- %%
- RotorE = 2.095e11; %转子弹性模量;
- RotorM = 7.85e3; %转子材料密度
- ShaftL = [0.25,0.25,0.1,0.2,0.2,0.1,0.2,0.2,0.1,0.25,0.25,0.2,0.2,0.1]; %各轴段长度
- ShaftDI = ones(1,Nshaft)*0.1;ShaftDI(3)=0.15;ShaftDI(4)=0.15; %各轴段外径
- ShaftDI(5)=0.15;ShaftDI(6)=0.15;ShaftDI(7)=0.15;ShaftDI(8)=0.15;ShaftDI(9)=0.15;
- ShaftDO = ones(1,Nshaft)*0.0; %各轴段内径;
- SPtype= 2; %支承类型选择, 1 -- 刚性支承, 2 -- 弹性支承;
- LocationF=[1,12]; %支承所在节点编号;
- SPstiffness=[5.0e7 5.0e7]; %支承刚度,SPtype = 1时,无需进行任何设置;
- %%
- addtionN = [2,3,6,7,9,10,14,15]; %附加轮盘编号
- addtionM = [70.1311,70.1311,144.1157,144.1157,70.1311,70.1311,70.1311,70.1311]; %附加轮盘质量
- addtionJ = [2.3888,2.3888,9.2324,9.2324,2.3888,2.3888,2.3888,2.3888]; %附加轮盘转动惯量
- %%
- CSN = 5;
- CriticalSpeeds=Chinavib_CriticalSpeeds(Nshaft,RotorE,RotorM,ShaftL,ShaftDI,ShaftDO,SPtype,LocationF,SPstiffness,addtionN,addtionM,addtionJ,CSN)
复制代码 计算结果如下:
CriticalSpeeds =
1.0e+004 *
0.1400
0.2180
0.4441
0.8866
1.0966
从结果上看,低阶临界转速计算结果略有增加,高阶临街转速略有降低,但是影响不大
[ 本帖最后由 论坛出品 于 2008-10-13 14:50 编辑 ] |