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in the integrator I say:

integrator Newmark 0.55 0.275625

I want know, if my model didn't converge, how can i reduce time step for integration.

excuse me, perhaps my question is very simple, but really I don't know.

in uniform excitation we must specify dt for input motion, in rec and sin how can i say to OS to apply load in dt=0.033 sec?

thanks.

one another question:

in rectangular and sin input motion, what is the dt for analysis? where can i say to OS to apply dt for input motion?

is that in analysis command?

my Structure is elastic, but my soil not:

freeimagehosting.net/uploads/1b26b6915e.png

I calculate freq and damp with three ways: *************************************************** 1- rectangular motion: *************************************************** *input motion is: pattern Plain 1 "Rectangular 0 [expr 20*$deltaT]" { load 2042 1000 0 0 } pic: freeimagehosting.net/upl...

I have been done that, but in some way it is give me different damping.

is damping calculated from ABS or REL is different?

I know.

I apply load for short time (for example 3 seconds) and let to vibrate for 50 seconds.

1- how can I pull the node? with initial displacement in OS?

Hi all, I want to calculate frequency and damping of my model with free vibration analysis. I have multiple choices for input motion and I examined these: 1- rectangular time series 2- sin time series 3- sinusoidal wave as an uniform support my question: 1- In case of 1 and 2 the output is absolute?...

I had this error,also.

I think you must change this line:

MACHINE_SPECIFIC_LIBS =

to this:

MACHINE_SPECIFIC_LIBS = -L/usr/lib/gcc/x86_64-linux-gnu/4.3

I compiled 1.7.3 , 1.7.4 , 1.7.5 and 2.

I think I found the problem. In the analysis I analyze a slice of a soil and base palate(2D analyze), but hole of structure(mass and stiffness). My base plate length in out of plane is 20 m (20 cm in scaled model ). I have been gotten a 1 meter of soil and base plate and hole of structure, while the...

this is an example: wipe all model BasicBuilder -ndm 3 -ndf 3 set nx 1 set ny 4 set nz 20 set e1 1 set n1 1 set dx 1.0 set dy 120.0 set dz 60.0 nDMaterial PressureIndependMultiYield 1 3 1.9 182590.0 852086.666667 10.0 0.1 21.4 50 0 -9 1.e-06 1 3.16e-06 0.913 1.e-05 0.761 3.16e-05 0.565 1.e-04 0.4 3....

I asked this question because I work on SSI problems .I have experiment results from laboratory test. My model is like below: freeimagehosting.net/uploads/cdfb754f8d.jpg freeimagehosting.net/uploads/024f60c0cb.jpg 4 type of structures(5,10,15,20 stories) lie on the two type of soil(Vs= 310,450). I u...

Dr. silvia!

please move this post to soil users.

thanks.

as I know:

kinematic SSI: mass density and stiffness of soil present, stiffness of structure present but mass of structure does not present. Is it true?

please see this my post:


opensees.berkeley.edu/community/viewtopic.php?t=12599

please excuse me for my poor english.

According to this book (SOIL-STRUCTURE INTERACTION), page 5, after equation (16.7) : csiberkeley.com/Tech_Info/16.pdf ------------------------------------------------------------------------------------------------------- Most structural analysis computer programs automatically apply the seismic loa...

please reply me.

when i use PressureIndependMultiYield material the analysis and Experiment is the same in free field analyze, but when i put the structure on it the analysis show different than Experiment. please help me.