I need your help.

[Nastiia]

Dear Sir/Madam,
I really hope that my question reaches someone, but if you are reading this, I will be immensely grateful to you. I would really like to understand how to solve such tasks.
I study at the university at the Faculty of Civil Engineering. I really need help from you if you are good at conducting cause-and-effect relationships in such drawing tasks in the subject Analysis of building structures.
The assignment is written in Czech, but I will translate it into English to make it more convenient:

Determine and plot the waveforms of the causal lines
Mf, Rb, M1, Q1 and Qdc.
Do not bind to shear.
(To check you need advice of all causal lines calculated in points I and II).

Your coefficients for the ANKC course:
a=0.700 , b=1.200 , c=1.400

I have attached a photo of the tasks below
Thank you so much for reading this. All the best and have a good time of day.

 

[GregLocock]

...and what is your progress so far? Why is this not covered in your lectures and textbooks? Since no loads are shown I suspect you are after influence diagrams, but I'm not sure.

I'd start by sketching out a shear force and bending moment diagram to get a few clues

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[Nastiia]

I have more of a question like this: how would I define numerical values of causal lines on statically undefined constructs. Due to not knowing how to calculate this, my progress on the problem has come to a halt.

 

[GregLocock]

causal lines is not a term I've come across. Can you give an example?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[Nastiia]

I send a screenshot from an example of statically determined casual lines

 

[GregLocock]

Ah the one with the green dashes - sort of partly complete free body diagrams?

https://en.wikipedia.org/wiki/Free_body_diagram

In your question where is the force applied?





Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[rb1957]

I too haven't heard this term in the past ... can you post the section in the text where they describe it ?

what is that sketch to the right of the beam ... another set of loads ?

the question mentions "moving system of forces" ... ??

What is Q'2 ?
maxmk1 ? (max moment @ k1 ?)
what are the kx points on the beam ?? supports ??
what are x1 and x2 ? (the limits of travel of the 10 force ?)

"Wir hoffen, dass dieses Mal alles gut gehen wird!"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[GregLocock]

I'm guessing the 2.1.4 question is talking about the influence line as a truck drives across the bridge. But that is a guess.

https://en.wikipedia.org/wiki/Influence_line

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[Nastiia]

I will send you screenshots of my materials from the university

 

[GregLocock]

So my interpretation is that a causal line is a plot of a selected property at a particular point (?) along the beam, as a function of the location of the force applied to the beam. The ? is because I would have thought knowing the max bending moment anywhere along the beam is more useful.

Anyway, fundamentally you are trying to solve the SF and BM diagram for one particular location of the force and then generalising it. So you know how to do the first part of that?






Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[rb1957]

yeah we call them "influence lines" for solving redundant structures, see

https://eng.libretexts.org/Bookshel...e_Lines_for_Statically_Determinate_Structures

but TLDR, sorry.

"Wir hoffen, dass dieses Mal alles gut gehen wird!"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.