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Hi, I want to find some material which is related to elastic nonlinear . I mean ,for example , when this elastic nonlinear material is set to a truss element ,it behaves like an element set to Material Steel02 when under pressure, and behaves like element set to Elastic Uniaxial Material . I am wond...

How to record the StrainStress of the truss element when I do the dynamic analysis of a space structure in Opensees ? I know there is a recorder command of element about stressStrain, but it is for section fiber ,such as the command :recorder Element -file Element1.out -time -ele 1 3 section 1 fiber...

I use the corotTruss element in a large span space structure in opensees. How can I deal with the buckling in corotTruss element when I do some dynamic analysis. Is there any other element or material in opensees related to this problem. Also, I want to know which papers I need to read in order to u...

how to get the start time and the terminal time of the transient analyze.i want to know how much time it costs to do the transient analyze. thanks a lot.

we use "pattern UniformExcitation $patternTag $dir -accel (TimeSeriesType arguments) <-vel0 $ver0>" commands to define the initial velocity at nodes, and this command set the velocity to all the nodes of the structure . I want to set the velocity to some of the nodes ,not to all of the nodes , is th...

I want to do some analysis about geometric nonlinearity in a structure built with truss element, however I get the linear result . so how to solve this problem. when I use the corotTruss element, I get the zero result , in this problem, an earthquake load is applied to the whole model. Is there any ...

there is a file named "Pext.txt" which contains the nodal load I want to apply, and the load varies according to the time.
my problem is how to add this load to a node which we can name it "node 2",and we suppose there is only one DOF at the node.
please write the commands if possible. thanks a lot.

1.Truss::addInertiaLoadToUnbalance(const Vector &accel)
2.Truss::getResistingForceIncInertia()
what is the relationship of the two classes above in Truss.cpp. and what result will get after invoke the two classes. thanks.

i used theNodes[0]->getDisp()

why i get 0 when i use the getDisp() class in element. is there any thing i forget?

how to get the nodal displacement of the committed step and the update step in my new element cpp. thanks a lot.

I want to get the midpoint load of the element or nodal external Load when formUnbalance.

In the code below, what does the " theEle->addMtoTang(c3)" mean ? why doesn't it get the M matrix from the trusselement for example. thanks a lot. int Newmark::formEleTangent(FE_Element *theEle) { if (determiningMass == true) return 0; theEle->zeroTangent(); if (statusFlag == CURRENT_TANGENT) { theE...

is there any flowchart of opensees for trusselement analysis, in which Newmark 0.5 0.25 is used.
i wonder how the classes are called .thank you very much.

sorry, i means the nth step and i+1 means the (n+1)th step,we can regard as the step at time t and the step at time t+deltat respectively.