Engine Vibration计算分析中load group说明


测试如上图所示,定义对转速10rpm 20rpm分别定义两个load group (在list文件中称为Generalized Force Vector).

同时包含load group1,2的位移结果为只包含load group1的位移结果的两倍,故认为load group概念相当于SACS中load condition(工况)下的load ID(荷载标签)。

测试3:GEN. FORCE VECTORS等于load group数目,同一load group的不平衡荷载相互叠加(对load group3:1+1=2,见如下所示list结果)。

                   **** ENGINE SPEED DATA FOR SPEED NO. 1 ****

                   SPEED .....................   10.00 RPM

……

  1. GEN. FORCE VECTORS .... 3

                             GEN. FORCE NO. ........... 1

                            HARMONIC NO. ............. 0

                             LOAD GROUP NO. ........... 1

                             INTERPOLATION TYPE .......LINEAR  

                   **** GENERALIZED FORCE AND MODAL RESPONSE ****

                          * UNBALANCED FORCE *   FREQ.     * MODAL RESPONSE *

   MODE   FREQ.     DAMP   AMPLITUDE   PHASE   RATIO     AMPLITUDE   PHASE

           HZ     PERCENT     KN         DEG                 CM         DEG

     1     2.149   2.000       1.000     0.000   0.078       4.2387     0.179

     2     3.681   0.000       0.000     0.000   0.045       0.0000     0.000

……

                             GEN. FORCE NO. ........... 3

                             HARMONIC NO. ............. 0

                             LOAD GROUP NO. ........... 3

                             INTERPOLATION TYPE .......LINEAR  

                   **** GENERALIZED FORCE AND MODAL RESPONSE ****

                           * UNBALANCED FORCE *   FREQ.     * MODAL RESPONSE *

   MODE   FREQ.     DAMP   AMPLITUDE   PHASE   RATIO     AMPLITUDE   PHASE

           HZ     PERCENT     KN         DEG                 CM         DEG

     1     2.149   2.000       2.000     0.000   0.078       8.4774     0.179

     2     3.681   0.000       0.000     0.000   0.045       0.0000     0.000

同时该测试也表明在engine vibration分析中每个转速相当于SACS静力分析中的load condition(工况)。