tailieunhanh - Pseudo Velocity Shock Spectrum Rules For Analysis Of Mechanical Shock

Place a small level on top of the compensating crank (photograph 1). Make sure that it is resting on a flat portion of the crank. If the compensating crank is not level, adjust the length of the restoring cable to make it level. After each adjustment, operate the gates back and forth several times to seat the restoring cable and then bring the gates back to exactly 50 percent. When the compensating crank is level with the gates at 50 percent, the black gate position needle should be at 50 percent. If it isn’t,. | Pseudo Velocity Shock Spectrum Rules For Analysis Of Mechanical Shock Howard A. Gaberson . . 234 Corsicana Drive Oxnard CA 93036 ABSTRACT I have taken on the job of recording the features and use of the pseudo velocity shock spectrum PVSS plotted on four coordinate paper 4CP . Some of the newer rules could be presented as a separate paper but knowledge of the PVSS on 4CP is so limited that few would understand the application. An integrated document is needed to show how all the concepts fit together. The rules cover the definition interpretation and accuracy of four coordinate paper simple shock spectrum shape drop height and the 2g line pseudo velocity relation to modal stress shock severity destructive frequency range shock isolation use with multi degree of freedom systems low frequency limitation of shaker shock and relation to the aerospace acceleration SRS concept. I hope that by showing you the wide applicability of PVSS on 4CP analysis that I can convince you to use it. Introduction Dick Chalmers Navy Electronics Lab San Diego CA and Howie Gaberson Navy Facilities Lab in Port Hueneme CA worked on shock during the late sixties to define equipment fragility and its measurement. Chalmers Navy experience in organizing severe ship shocks by induced velocity led us to an independent discovery that induced modal velocity not acceleration was proportional to stress. We published that in 1969. Earlier others had discovered and written on the same subject. No one paid any attention. At Chalmers insistence in the early 90 s we started pushing the concept again and we connected it to the pseudo velocity shock spectrum plotted on four coordinate paper PVSS on 4CP a 1950 s concept. Matlab came along and made the PVSS calculation and 4CP plotting easy. It turns out that PVSS indicates multi degree of freedom system modal velocity through a participation factor. Dick died in 1998 but his results are certainly in this paper. PVSS on 4CP was used at least in the late