What is Stiffness: Definition and 171 Discussions

Homework Statement node1 node2 O---------------------------------------O a rod with 2 nodes: x1=axial force at node1 x2=axial force at node2 u1,axial deflection at node1 u2,axial deflection at node2 l=elements length E=young's modulus...

Hello... I have a 6x6 stiffness matrix. I also have a 3x3 matrix containing the direction cosines of the x',y', and z' reference system. My question is: How can I transform my 6x6 stiffness matrix or how can I get a 6x6 transformation matrix?

I know that stiffness is load per unit deflection. I have the load versus deflection curve for a steel plate. Is it possible for me to find the stiffness of the plate? Thank you.

Homework Statement A 65 kg trampoline artist jumps vertically upward from the top of a platform with a speed of 5.0 m/s. (Ignore small changes in gravitational potential energy.) a) How fast is he going as he lands on the trampoline, 3.0 m below? ANS: 9.2m/s NOTE: I understand how to get...

Hi, I am trying to write a MATLAB script to do an elastic analysis of 3D frame sturctures. The method I am using is the direct stiffness method, but I cannot find the equations for the 12x12 stiffness matrix for each member in the global system. If anyone has any information on 3D matrix...

Hi all: I am fresh to engineering and have basic question. I have a 100 inch length and 40 inch wide & 6 in depth plate , it has honeycomb structure what I mean 0.125 inch face sheet of aluminum on either side and rest (6-.125*2)is honeycomb made of alumnium.It is supportted on 4...

Dear All, I need to represent a hydraulic system into an equivalent mechanical (spring-mass-damper) system. But actually, they have reverse analogy in terms of flow resistance and stiffness.. meaning, Force=stiffness(k)*displacement; but Flowrate=(Pressure drop)/Flow resistance i.e...

Homework Statement Problem is (to be solved in software, this is actually a programming assignment): -\triangle u = f on \Omega = (0,1)^2 u = 0 on \delta\Omega And f = 2x(1-x)+2y(1-y) And the exact solution known to be u(x,y) = x(1-x)y(1-y) Okay, so the actual assignment is about...

Hi all, I am doing a research project on how vertical tractional forces (applied at the tail of rats) affect scoliosis. I know the lateral deviations for each weight at specific columns of the spinal cord...however, I want to assess the lateral force at each specific point due to the vertical...

I spent almost 2 days to solve the following stiffness matrix \left(\begin{array}{c}f1\\f2\\f3\\f4\\f5\end{arr ay}\right)=\left(\begin{array}{ccccc}20&-20&0&0&0\\-20&40&-20&0&0\\0&-20&40&-20&0\\0&0&-20&40&-20\\0&0&0&-20&20\end{array}\right)\left(\begin{array}{c}0\\d2\\d3\\d4\\0\end{arr...

how can we increase or decrease the stiffness of a spring

I get the urge to crack my neck once everyday to relieve the stiffness. The urge is even stronger after I put in some good hours of reading or computer related activities. And man does it feel good! But I fear that there may be some medical implications to this. Like maybe tearing something...

Iv done an experiment with a spring wher you add mass and record the new length. From a table of these rusults iv plotted length (m) against mass (kg), like so Now i have to calculate the stiffness, k, from this graph with the equation: mg = k (l - lo) so just to varify that what iv...

Homework Statement A mass m hangs from a spring with stiffness constant k. The spring is cut in half and the same mass hung from it. WIll the new arrangement have a higher or a lower stiffness constant than the original spring? Homework Equations F= -kx The Attempt at a Solution...

Would I be correct in saying "Material stiffness - the ability of a material to resist bending when subject to compressive AND tensile forces"... especially the last bit. Thanks in advance.

Why would a rope have a lower bending and compressive stiffness that a rod of the same diameter, but would have the same axial tensile stiffness?

I require a detailed understanding of the stiffness matrix in the analysis of rods,beams et In the beginning of stiffness matrix derivation the textbooks say force at ith degree of freedom(dof) to hold unit displacement at jth dof when all other dofs are zero. let us analyse this...

I want to derive the theory of finite element using my own understanding. With this derivation i want to understand the fea theory of rod element I call the nodes as "points" in a structure. This scenario is for a simple one dimensional displacement of points(that is the single degree of...

many references tell that the dynamic stiffness will reduce when vibration amplitude increases. And the experimental result is just so. But why there is such rule?who can explain it theoretically?

i have put this question in other forum also. I have understood the stiffness matrix generation for a single rectangular element as below. I consider each node having 2 translational dofs each in x and y coord system. There are 4 nodes in this rectangular plate element and hence 8 dofs...

i know that the stiffness for a line element is calculated as fl/ae where a is known as area and l is the length,f is the force applied and e is the youngs modulus. How the stiffness of a plate element are calculated?