lifting calculations

[exxon]

... I can't understand the mathematical motivation behind us...

Mathematical motivation comes from the annulment of moments of reaction to extremes. with symbols in the figure,
because but and mb must be necessarily null (otherwise the system would enter into rotation), you can write

(b) = 0
(a + b)
(a + b)

Similarly, by canceling the mb moment, you can write

(b) = 0
(a + b) =
(a + b)

 

[pollo]

eye that contemporary shots must be designed from time to time and it is not said that you can use the usual file/model

 

[zuzu1977]

with the geometric assumptions indicated above, i.e. that you simply consider the rectangular plant with random baricentro inside the rectangle you can have a simple calculation made as below.
View attachment 53836with the rules of the lever you calculate first thing pab=p•d/(c+d).
then it is calculated accordingly pa=pab•b/(a+b)....
I ran a little bit, but I hope there's no mistakes... .

hi, I refer to this post that was very helpful to me.
In my case I have a machine with known dimensions and baricentro, if between pa and pb I have one or more points of support, how should I calculate the respective load?
Thank you!

 

[meccanicamg]

hi, I refer to this post that was very helpful to me.
In my case I have a machine with known dimensions and baricentro, if between pa and pb I have one or more points of support, how should I calculate the respective load?
Thank you!

through the equations of construction science. doing it by hand becomes complicated. using a program that calculates on its own would be the best. or simply do not consider them, to safety reason and you are appropriate.