search

rclab-auth / gidopensees

GiD+OpenSees Interface
http://gidopensees.rclab.civil.auth.gr
GNU General Public License v3.0
94 stars 42 forks source link

static load and dynamic load #66

Closed haldarsumanta closed 5 years ago

haldarsumanta commented 6 years ago

I have modeled a 1 m length cantilever beam using GiD. I want to apply the static load at the free end of the beam at interval 1. At interval 2, I would like to apply cyclic (sinusoidal) displacement at the free end. I could not find any option to incorporate it. Please suggest.

test.zip

theokart commented 6 years ago

I guess the static load corresponds to the gravity. Choose Newton-Raphson algorithm with Load control and apply this in a few steps (i.e. 5 steps) and check the option "keep load active..." in the first interval options. Create a second interval (do not copy conditions) using Transient analysis and select Multiple support excitation as the loading type. Moreover, assign "Sine ground motion", through Loads option determining the period and the duration of this loading, to the free end. (Its not ground motion but it will work for your purposes since it just imposes the desired displacement). Set the analysis duration to greater or equal to the loading duration. Since mass is zero (works like a static analysis), setting analysis duration greater than loading duration is unnecessary. So, add mass (in first interval!) if you want to estimate the dynamic behavior.

haldarsumanta commented 6 years ago

I guess the static load corresponds to the gravity. Choose Newton-Raphson algorithm with Load control and apply this in a few steps (i.e. 5 steps) and check the option "keep load active..." in the first interval options. Create a second interval (do not copy conditions) using Transient analysis and select Multiple support excitation as the loading type. Moreover, assign "Sine ground motion", through Loads option determining the period and the duration of this loading, to the free end. (Its not ground motion but it will work for your purposes since it just imposes the desired displacement). Set the analysis duration to greater or equal to the loading duration. Since mass is zero (works like a static analysis), setting analysis duration greater than loading duration is unnecessary. So, add mass (in first interval!) if you want to estimate the dynamic behavior.

Thanks for your reply. The static load is not gravity. It is a point load applied at beam node. In case of 2nd interval, how to apply a sinusoidal displacement at the specific nodes of the beam?

vpapanik commented 5 years ago

you can use displacement of 1 in that node and use a scaling function as loading