Determine the resultant internal loadings in the crane

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Homework Help Overview

The discussion revolves around determining the resultant internal loadings in a jib crane, specifically focusing on the boom DF and column DE, which have a uniform weight. The problem involves calculating forces at specific cross sections (A, B, and C) given the weights of the crane components and the load being lifted.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the calculation of forces acting on different sections of the crane, questioning the appropriateness of the weights used in their calculations. There is a focus on whether the total weight of the boom or just a segment is relevant for specific points.

Discussion Status

Some participants have provided feedback on calculations, indicating areas where assumptions may need to be reconsidered. There is an ongoing exploration of the correct approach to determining forces at specific points, with no clear consensus yet on the methods being used.

Contextual Notes

Participants are working within the constraints of uniform weight distribution and specific load values, with some questioning the interpretation of these weights in relation to the cross sections being analyzed.

jjiimmyy101
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QUESTION: The boom DF of the jib crane and the column DE have a uniform weight of 50 lb/ft. If the hoist and load weight 300 lb, determine the resultant internal loadings in the crane on cross sections through points A, B, and C. (Diagram and answers are attached)

I'm just hoping someone could look at what I did and tell me if I did it correctly.
 

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Here's point C
 

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Looks good to me, but did you take the correct weight for DC in your calculation of point C?
 
The boom DF of the jib crane and the column DE have a uniform weight of 50 lb/ft.

What I did was find the force acting on the entire beam DF, not just DC.
That's why I got 650 lb (50lb/ft*13ft and it acts @ 6.5ft). Is that the right way to do it? And I was wondering if that force I put right on point D is correct. Thanks for the input.
 


Wouldn't the downward force placed at D be 250 lb?

There is 5 feet of column above cross-section C. So wouldn't you multiply (5 ft)*(50 lb/ft) = 250 lb?
 

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