Partial distributed load over fully fixed beam

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Discussion Overview

The discussion revolves around calculating the deflection of a fully restrained beam subjected to a partial distributed load. Participants explore methods for determining the deflection curve based on reaction forces and moments, as well as the integration of bending moment equations.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Homework-related

Main Points Raised

  • One participant seeks assistance in relating reaction forces and moments to the deflection of a fully restrained beam.
  • Another participant suggests that the deflection curve can be calculated by integrating the bending moment curve twice and applying boundary conditions to find constants of integration.
  • A participant presents a specific equation for the reactionary force but expresses uncertainty about where to integrate within that equation.
  • One participant corrects the terminology used by another, clarifying that 'reactionary' should be 'reaction force' and emphasizes the importance of constructing a bending moment diagram before integration.
  • The same participant also notes that boundary conditions must be applied to determine the constants of integration, specifically that both the slope and deflection at the beam's ends are zero.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the specifics of the integration process or the terminology used, indicating that multiple viewpoints and some confusion remain in the discussion.

Contextual Notes

There are unresolved aspects regarding the application of boundary conditions and the specifics of the integration process, which may depend on the definitions and assumptions made about the beam's loading and support conditions.

aqpahnke
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I am trying to figure out the deflection in a fully restrained beam. A diagram of the beam can be found here on this website.
http://civilengineer.webinfolist.com/fb/fbcalcu.php

I have been able to find the reactionary forces as well as the moments at each end of the beam for any distributed load at any position on the beam.
I would like to relate this to the deflection of the beam at any point and am completely stuck.
If any of you have the know-how please help out.

Aric
 
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If you have determined the reaction forces and moments which keep the loaded beam in equilibrium, then you can calculate the deflection curve of the beam by integrating the bending moment curve twice w.r.t. length and applying the boundary conditions to determine the unknown constants of integration, just like any other beam problem.
 
Okay.. let's say that on that particular beam that the reactionary force for one direction is R1= (q*d/L^3)[(2b+L)a^2-((a-b)/4)d^2)]
I get stuck on the particulars. I don't really know where to integrate in this equation
 
Okay.. let's say that on that particular beam that the reactionary force for one direction is R1= (q*d/L^3)[(2b+L)a^2-((a-b)/4)d^2)]
I get stuck on the particulars. I don't really know where to integrate in this equation
 
'Reactionary' means something else than what you assume. The proper terminology in English is 'reaction force'.

http://en.wikipedia.org/wiki/Reactionary

You misunderstand the procedure to follow in analyzing beams to determine deflections. Once you have determined the end reactions and moments, you construct the bending moment diagram for the beam, using the end reactions and moments. This bending moment diagram, or the functions which generate it, is integrated twice w.r.t. the length coordinate, say x. After each integration, an unknown constant of integration is obtained, which constants can be calculated by applying the boundary conditions for the beam. In this case, both the slope and deflection of the beam will be equal to zero at each end.

Have you studied any strength or materials courses?
 

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