I am trying to model a simple dampened spring system with a mass under its own weight except I want the damping to be drag, thus proportional to velocity squared.
m y"(t) + c y'(t)^2 + k y(t) = W
When I graph the solution on MathCAD, it never decays, it is an endless oscillation. Any ideas?
When checking the combined inplane stresses with lateral load(3.6), there are the four conditions (tension-tension, tension-compression,etc.) and then it says a Von Mises check also applies, Equation 3.6-5. However, the denominators in the unity equation are fcr, not Fy. What does buckling...
I want to change data from this
Row Column Value
1 1 5
1 2 6
2 1 7
2 2 8
to this:
Row Column
1 2
--- ------
1 5 6
2 7 8
I cant seem to figure it out...
I am trying to do buckling strength analysis of an unstiffened plate with lateral pressure and inplane stress. DNV RP-201 looks to be appropriate but I am concerned it only applies to plate supported at all 4 edges.
Anything I am missing, or a correction factor?
I was thinking of maybe...
I am trying to draw a set of curves for a two parameter system.
x:=1,2..3
y:=1,2..10
f(x,y):=x*y^2
I want lines for x=1,2,3. My mathcad guide says you can get rid of the "flyback" to zero using the draw option in the plot menu but I cannot find it anywhere.
Anyone know some good tips for...
If I have
x:=1,2..4
y:=x+1
x=1,2,3,4
y=2,3,4,5
I can do max(y), but how do I get it to return what x causes the max?
I cannot do differentiation because I have a more complex equation with absolute value and thus is discontinuous.
Thanks
Is there any way to tell Mathcad that you want to treat an expression as a variable only? For instance I want to define KL/r as a variable, and it keeps thinking I trying to write a formula KL divided by r.
What do you guys use to make sketches such as free body diagrams, etc.? Other than Autocad or crummy MS Paint...preferably something that has drawing symbols such as c.g. and stuff like that
Thanks
Anyone have any reference material on how to design a ring stiffener for a girder welded to a tubular column, such as an offshore deck leg girder connection? Do you use Roark case 1 for circular rings?
PC Engineers has a small program but I want to see the basis for their calculations...
Anyone have any reference material on how to design a ring stiffener for a girder welded to a tubular column, such as an offshore deck leg girder connection? Do you use Roark case 1?
PC Engineers has a small program but I want to see the basis for their calculations...
According to Von Mises if you have a steel cube under hydrostatic stress only, it will never fail no matter how much stress you put on it.
How is this reconciled in real life? Is there a "cap" to Von Mises?
What is the story here?
For some reason I cant get this to work out. If you have a spring and you apply a P weight in the axial direction, the strain energy in the spring is
Us = 1/2 Px (or 1/2 kx^2)
But the work done by gravity is
W = P x
But Us does not equal W? Maybe this does not account for the effect of...
If there is a way to do P-delta and Soil-structure interaction at the same time in SACS, I have not figured it out. Is it possible to do this? Do other programs allow a simultaneous p-delta and ssi interaction?
How do you determine the moment capacity of a beam with equal tension and compression reinforcement? All the examples I've seen have more tension than compression steel and the beams are broken into two separate beams, but there is no "second" beam here as there is no excess rebar...
I am would like to determine the wave force on the side of a barge (170' x 40' x 8'). Morisson theory is good for slender members but what about long flat plates?
Thanks
In LRFD you can develop a fully plastic section in bending. However, when you do a linear analysis using structural software the structure is assumed linear. Thus, does this force you to do a non linear analysis, or are the plastic sections so isolated that there is not much difference?
If you know the wave height for a specific return period, how do you solve for the height at another return period? I know you must assume some distribution...what distribution is typically assumed?
