Force method and displacement method are the same problem
Publish: 2021-05-06 22:17:35
1.
I saw it at noon. Now I pass the picture, the answer may be wrong, but it's just a process
2. Both methods are used to solve statically indeterminate structures, but displacement method can also be used to solve statically indeterminate structures
the force method takes the rendant unknown force as the basic unknown quantity, and transforms the statically indeterminate structure into statically indeterminate structure by selecting the basic system. The force method equation is the deformation compatibility equation, so it is not easy to compile a unified computer program and solve the statically indeterminate structure for many times< The displacement method takes the displacement (angular displacement, linear displacement) as the basic unknown quantity. There are two solutions: one is the direct bending moment balance method, the other is the basic system method; The additional rigid arm (black triangle symbol) and "additional strut" limit the angular displacement and linear displacement, and the basic system is a higher order statically indeterminate structure; The displacement normal equation established by the two methods is the same, and the displacement normal equation is an equilibrium equation; The derivation methods of displacement method include moment distribution method, non shear distribution method, matrix displacement method, etc. matrix displacement method is the application of computer to solve statically indeterminate problems, which can be used to solve large structures
these are the main things I think of.
the force method takes the rendant unknown force as the basic unknown quantity, and transforms the statically indeterminate structure into statically indeterminate structure by selecting the basic system. The force method equation is the deformation compatibility equation, so it is not easy to compile a unified computer program and solve the statically indeterminate structure for many times< The displacement method takes the displacement (angular displacement, linear displacement) as the basic unknown quantity. There are two solutions: one is the direct bending moment balance method, the other is the basic system method; The additional rigid arm (black triangle symbol) and "additional strut" limit the angular displacement and linear displacement, and the basic system is a higher order statically indeterminate structure; The displacement normal equation established by the two methods is the same, and the displacement normal equation is an equilibrium equation; The derivation methods of displacement method include moment distribution method, non shear distribution method, matrix displacement method, etc. matrix displacement method is the application of computer to solve statically indeterminate problems, which can be used to solve large structures
these are the main things I think of.
3. And what<
the force method removes the middle part and replaces it with the unknown force
in Tongji's structural mechanics, mechanics begins with this
as you can see, I'm not good at using scientific symbols
the displacement method is suitable for rigid frames, but it's not suitable, but it can also be used to limit the rotation angle of the middle arm
without considering the axial deformation
it can be brought in by the rotation displacement equation
the force method removes the middle part and replaces it with the unknown force
in Tongji's structural mechanics, mechanics begins with this
as you can see, I'm not good at using scientific symbols
the displacement method is suitable for rigid frames, but it's not suitable, but it can also be used to limit the rotation angle of the middle arm
without considering the axial deformation
it can be brought in by the rotation displacement equation
4.
The force method is based on the displacement and deformation conditions corresponding to the rendant constraints; The displacement method is based on the equilibrium condition of unknown node displacement; Both methods are used to solve statically indeterminate structures, but displacement method can also be used to solve statically indeterminate structures
5. In the displacement method, the bending moment at the rod end is clockwise; Shear force (in order to make the section in clockwise rotation is positive, the provisions of material mechanics remain unchanged).
6. Generally speaking, I forgot about it. The method of force needs to calculate by Graph Multiplication, which is very troublesome to draw and calculate area, especially when several forces act together. The balance equation of force method is also very complex and difficult to solve, but all geometrically invariant structures can be solved by force method
the form constant and load constant of the displacement method are calculated by the force method, which is equivalent to directly using a conclusion, which saves one step compared with the force method, and the balance equation of the displacement method is also better solved. If you have calculated in civil engineering, you must have realized it. That's all. You can only find the rest by yourself!
the form constant and load constant of the displacement method are calculated by the force method, which is equivalent to directly using a conclusion, which saves one step compared with the force method, and the balance equation of the displacement method is also better solved. If you have calculated in civil engineering, you must have realized it. That's all. You can only find the rest by yourself!
7. I've never met
all kinds of methods can only be used for checking calculation
the answer will not be bad
all kinds of methods can only be used for checking calculation
the answer will not be bad
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