Strain characteristics of tie rods

In the low speed area, the tie rod shoulders are not all in contact with the tie rod holes on the wheel. At this time, the larger the static installation clearance, the higher the maximum equivalent stress value of the tie rod; after reaching the turning speed, all the shoulders are in contact with the tie rod hole. Contact; in the middle speed area, the maximum equivalent stress of the tie rod rises slowly with the increase of the speed, and does not change with the static installation clearance; after entering the high speed area, the shoulder at the end of the tie rod occurs due to the limitation of the external countersunk head The large warpage makes the maximum equivalent stress value of the tie rod increase rapidly with the increase of the speed. The purpose of dividing the speed range is to grasp the change of the rod stress in each speed range, and at the same time, it is convenient to set the operating speed of the rotor so that it is in a lower stress state.
Before the ultimate load is reached, the strain of the restraint rods is small, the restraint rods in the first row and the third row are basically in the elastic working stage, and the restraint effect of the rods on the steel pipe wall is relatively small. After reaching the ultimate load, the restraint rods in the E row The strain develops rapidly and reaches yield soon, the curve is bent, and there is a long horizontal section, which shows that the third and third rows of tie rods have obvious restraint effects on the steel pipe wall. Since the first row of tie rods of the specimen is laterally constrained by the loading plate, its strain The development is slow until the specimen is completely destroyed, and the first row of tie rods still has not reached yield.