I can’t understand how the bending moment formula is derived; I need help
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As the title says. The graph is as follows; how does 4-17 come about? Can’t understand it
1. The mechanical model of a horizontal container is a simply supported beam with one end supported by a movable hinge and the other end by a fixed hinge. . 2. The bending moment at a section is numerically equal to the algebraic sum of the moments exerted by the external forces acting on the part of the structure to the left (or right) of that section. 3. Bending moment = Force × Lever arm
Questions: 1. Why is the hydrostatic pressure equal to Ri*q? 2. Since the hydrostatic pressure is equal to Ri*q, and according to the formula torque = force * lever arm… Why isn’t the bending moment equal to Ri*q*L/2, but instead becomes Ri*q*Ri/4?
It’s possible that integral calculations will be needed, because with an ellipsoid, it’s not possible to simply perform algebraic additions; it’s just a guess
1. The static pressure on the surface of the vertical head is Riq; however, after integrating the forces acting on the head portion, the value becomes Go. 2. But at the centroid of the head (at the horizontal coordinate hi3/8), GoX3/8hi = qRi^2/4
I don’t understand integrals; I just want to know how Go came about. Question: 1. I see that in calculations 4-16, the moments are calculated up to the middle cross-section of the tank, but why is the moment here calculated only up to the surface where it connects to the head (since only 3/8hi is used instead of (3/8hi + L/2))? 2. Please take another look at Equation 4-16. I have no doubts regarding the plus sign, but I’m unsure about the last parenthesis – why is it (L/2-A/2) instead of (L/2-A)? Could you help clarify this? Thank you! This article also includes sections 4-18 and 4-19, which have not been screenshotted; all calculations are based on the cross-section through the center of the tank.
Yes, integrals are used; I don’t understand integrals, but an expert said they are necessary.
This post was last edited by Forgetting = Forgetting on 2021-8-20 at 12:00. The first question: the bending moment caused by horizontal hydrostatic pressure; the second question: this point is the center of force, and there should be a detailed explanation of this in the book you’re reading
Thank you! Now I finally understand; it’s a horizontal force. Oh my god, no wonder it’s specified as (clockwise) at the end of the formula ； I also understood the second question; it’s all calculated based on the distance from the center of gravity. Thank you!
Are you reading the book by Li Jianguo?