Although it is usually easy to figure out in simple cases, it can be quite tricky. Fortunately, you rarely need to. Just make a stab at it in each case and write the equations accordingly. If the answer comes out negative then you guessed wrong, but so what? You still have the answer.tandennis0703 said:
I did ask you to type in your algebra. I am having trouble reading some of the image, and if I want to comment on an equation I have no easy way to refer to it.tandennis0703 said:
Sorry for the mistakes. I never took statics in my course. I redid everything and used the method of summing the resultant forces in both the x and y direction. I am still a bit confused as to how to figure out whether or not it is a compression/ tension force. Hopefully my calculations are correct.
haruspex said:
According to what you calculated at joint A, is AB under compression ortandennis0703 said:
Now I can read it, it all looks right.tandennis0703 said:
haruspex said:
In general, yes. As I posted, it is not always possible to figure it out by simple inspection.tandennis0703 said:
To calculate the forces in a truss, you first need to identify all the external forces acting on the truss. This can include applied loads, reactions at supports, and self-weight of the truss. Once you have all the external forces, you can move on to solving for the internal forces in the truss members.
The most common method for calculating the forces in a truss is the method of joints. This involves analyzing each joint in the truss and applying the equations of equilibrium to solve for the forces in each member connected to that joint. Another method is the method of sections, which involves cutting the truss into sections and analyzing the forces in each section.
Yes, there are many computer programs and software available that can calculate the forces in a truss. These programs use numerical methods to solve for the forces and can handle complex truss structures. However, it is still important to have an understanding of the principles and methods used in truss analysis to interpret the results from these programs.
The weight of the truss itself is considered an external force and should be included in the analysis. This can be done by breaking the truss down into smaller sections and considering the weight of each section as an applied load. Alternatively, you can also consider the weight of the entire truss as a distributed load and apply it to the joints in proportion to the length of each member.
Yes, there are a few assumptions made when calculating the forces in a truss. These include assuming the truss is in equilibrium, that all the members are connected by ideal pins or hinges, and that the members are only subjected to axial forces. Additionally, truss analysis assumes that the joints are rigid, meaning they do not deform under the applied loads.