Structural Analysis Problem- internal hinge

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The structure in question is not in static equilibrium once load "P" is applied, causing the roller at "D" to act as a fulcrum and lift the ABC structure. The initial assumptions included two reactions at "A," no reactions at "B," and one reaction at "D." However, it was pointed out that there should actually be a reaction force at "B" (By) due to the roller's constraints. Additionally, the moment at the frictionless hinge (point C) is always zero, which is a crucial factor in the analysis. The user seeks clarification on their calculations and how to determine Ax.
ride5150
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Homework Statement



hwquiz4.jpg



The Attempt at a Solution



for part 1:

i figured that this structure is not in static equilibrium. once load "P" is applied, the roller at "D" will function as a fulcrum and ABC will lift (make an angle with the horizontal).

is that assumption correct?

based on what i assumed:

i assumed:

2 reactions at "A", -Ax and -Ay
0 reactions at B
1 reaction at "D", Dy

i summed the moments about "D"

(clockwise moment is negative)

(-PL)+(Ay4L)=0

Ay= -P/3L ========================

Sum of forces in Y direction = 0:

Ay+Dy-P= 0

Dy= P-Ay

after substituting for Ay:

Dy=(3PL+P)/(3L) =========================

i don't know how to find Ax.

is what i did so far correct?

help please
 
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ride5150: That is currently incorrect. There is one reaction force at B, which is By. A roller symbol means a structure is constrained in the direction perpendicular to the roller, regardless whether the roller is in compression or tension. Hint 1: The moment at a frictionless hinge (point C) is always zero.
 

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