Patent ID: 11965858
Assignee: JFE STEEL CORPORATION
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 3:
4. The elastic matrix determination method according to claim 3, including
a first step of producing a laminated iron core to be tested formed by laminating steel sheets,
a second step of performing a vibration test while variously changing the average tightening pressure in the laminating direction of the produced laminated iron core to be tested to measure an actual value of a natural frequency of a specific vibration mode and obtaining a relationship between the natural frequency of the specific vibration mode and the average tightening pressure,
a third step of performing a structural analysis of the laminated iron core to be tested a plurality of times using structural analysis software with the shear modulus as a parameter to estimate a relationship between the natural frequency of the specific vibration mode and the shear modulus considering slippage between the laminated steel sheets,
a fourth step of obtaining a relationship between the average tightening pressure and the shear modulus from the relationship between the relationship between the natural frequency of the specific vibration mode and the average tightening pressure obtained at the second step and the relationship between the natural frequency of the specific vibration mode and the shear modulus estimated at the third step, and
a fifth step of using the relationship between the average tightening pressure and the shear modulus obtained at the fourth step to determine the shear modulus of each of the yoke portions and the leg portions depending on the average tightening pressure in the laminating direction on each of the yoke portions and the leg portions of the laminated iron core for transformers.