The issue of determining the value of h in the calculation of ear-type supports
Thread Content
When calculating the actual load carried by ear-type supports, according to Appendix A of JB/T 4712.3, how should the height h from the point where the horizontal force acts to the bottom plate be determined? Does the position where the horizontal force acts refer to the height of the center of gravity? If the center of gravity is above the support, h takes a positive value. When the center of gravity is below the support, should h be taken as a negative value? It will affect the calculation results. I seek guidance from experts, thank you. Also, after meeting the requirements as calculated in Appendix A, is it still necessary to calculate the local stresses in the cylindrical body?
In my understanding, there is a \"height h from the point where the horizontal force acts to the bottom plate\" only when a horizontal force is present.
One more question: can the ear mount be used as a lifting lug during lifting?
Generally, there should be no problems. If there are any issues, perhaps the lifting lugs need to take into account dynamic load factors, and the lug seats should be calculated based on the operating mass. It’s not clear whether a load factor of 1 or something else should be used. However, it’s important to note that during operation, all four lug seats are usually used together, but when lifting, only two points may be utilized, which could lead to problems
It’s still unclear whether h will take a negative value; please advise, experts
The bending moment caused by p*h results in tension on one side of the support and compression on the other side. So I think, regardless of whether it’s upper or lower, taking the positive value is sufficient; the negative value should not be used.
What to do if the minimum wall thickness of the cylinder does not meet the requirements when installing the lifting lugs?
Where is the minimum wall thickness specified?
According to HG/T21574-2008, for shaft-type lugs, the minimum wall thickness δmin of the cylinder at the lug location is specified in Table 9.2-2