Need fast help, (solid mechanics)

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Discussion Overview

The discussion revolves around calculating tensions in a statically indeterminate construction using finite element method (FEM) calculations and hand calculations in solid mechanics. Participants explore methods for analyzing structures that are not trusses and address the differences between truss and non-truss constructions.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant seeks methods to calculate tension in beams of a statically indeterminate structure, questioning the differences from truss constructions.
  • Another participant suggests dividing the structure into symmetric and asymmetric parts and solving along the symmetry axis as a potential method.
  • A participant points out the need for more than three equilibrium equations due to the hyperstatic nature of the structure.
  • It is mentioned that additional equations for compatibility of movements at supports may be necessary to solve the problem.
  • One participant raises a separate problem involving a thin plate with a central hole, asking for help with stress distribution and deformation analysis.

Areas of Agreement / Disagreement

Participants express differing views on the methods to approach the problem, with some suggesting specific techniques while others highlight the limitations of equilibrium equations. The discussion remains unresolved regarding the best approach to calculate tensions in the given structure.

Contextual Notes

Participants reference the method of sections for trusses, but the applicability to the current problem is questioned. The discussion includes assumptions about the structure's behavior and the need for additional equations, which are not fully resolved.

paul-martin
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Hi. We are doing a project in school with FEM calculation, and i am off to validate the tensions in the construction, but i do not know how i get the tension in the construction by hand calculation seen it is statically indeterminate, and it isn’t a truss.

My question is how can I calculate the tension for the beams?, (what method do I have to use)

What is the diffrent's from a truss construction in a solid mechanics point of view?

http://img197.exs.cx/img197/8416/problem.jpg
 
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paul-martin said:
Hi. We are doing a project in school with FEM calculation, and i am off to validate the tensions in the construction, but i do not know how i get the tension in the construction by hand calculation seen it is statically indeterminate, and it isn’t a truss.

My question is how can I calculate the tension for the beams?, (what method do I have to use)

What is the diffrent's from a truss construction in a solid mechanics point of view?

http://img197.exs.cx/img197/8416/problem.jpg

It seems to me the typical problem to divide the structure into a symmetric part and another asymmetric part, and solving cutting the structure by the symmetry axis. Are you familiar with this method?
 
Clausius2 said:
It seems to me the typical problem to divide the structure into a symmetric part and another asymmetric part, and solving cutting the structure by the symmetry axis. Are you familiar with this method?

Thx;l i have read about it, i will think about it, if you can please answer the outer questions.

Kindly Paul-M
 
paul-martin said:
What is the diffrent's from a truss construction in a solid mechanics point of view?

Could you rephrase your question? It doesn't make a whole lot of sense as to what you are asking.

Have you looked at the method of sections for trusses?
 
FredGarvin said:
Could you rephrase your question? It doesn't make a whole lot of sense as to what you are asking.

Have you looked at the method of sections for trusses?

It isn't a truss, my problem is that i need more then the 3 equilibrium equations.
 
paul-martin said:
It isn't a truss, my problem is that i need more then the 3 equilibrium equations.

I have looked for the translation of "truss" in spanish, but sure you would laugh at it if I tell you what that means in spanish.

Sure your structure is hyperstatic. You only have 3 equations for static equilibrium, and 6 unknown forces on each support.

When one finds this kind of situations, you must write additional equations for Compatibility of Movements of the supported extremes. For instance you know that the left bottom support cannot neither rotate, neither go upwards, nor go downwards. These three conditions give you the three additional equations you need. Another method of resolution would be therefore to release the left support (leaving it being suspended in air) and so your structure will be Isostatic. In particular, you will have three unknown forces acting on this support (one vertical, another horizontal and a bending moment).
 
hiiii its me peer...i need some help to solve dis problem.
A thin plate containing a central hole is made of an elastic and perfectly plastic material with youngs modulus E=200GN/M,Poissons ratio v= 0.3 and yield strength infinity=100MPA, D=0.4M,L=2M,W=1.2M.THE THICKNESS OF PLATE IS 0.01

A. find the applied remote stress (infinity) that leads to the initial yielding of any where in the plate.show the distribution of von mises and deformation of the plate at this applied stress.
B.find the maximum possible stress (infinity) that the plate can carry before full plastic collapse.show the distribution of von mises stress and deformation of the plate immediately before this applied stress is reached.
 
any 1 please reply me soon as possible
 

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