Thank you sir for your reply.

I work in a company so i can not share any photograph.Ignore my previous query.I am doing RS Analysis for single body looks like cylinder weighing 272 kg,it has 8 holes,i gave fixed support for those.the body contains 182210 nodes,111587 elements,0.81 avg  element quality,0.264 avg skewness and my first 10 natural frequencies are 274.77,432.69,467.98,522.82,621.35,672.53,782.26,820.74,839.13,843.46 and it ranges up to 9050 Hz ,300 modes were extracted,mass participation ratio 0.95 ratio in z direction,same loading condition as above,i got max stress at holes(fixed support) 669 Mpa,avg stress of body 95 Mpa,min stress 15 Mpa,i have continues stresses around 200Mpa over comparable area,i kept rigid response effect to off,i got top of the body directional accerlation min 13515 m/s2 and avg 38887 m/s2,max dir acc 101580 m/s2 in z direction.i used SRSS as mode combination method and i am pretty sure it is not because of stress singularity (due to meshing).

I have doubts that is the simulation is correct and which type of mode combination method i should use,if rigid response effect is on what should be Rigid response effect freq begin and end.

i am using licensed version 2022 R1