Dear all,
I have a rigid body and tried to include its mass into my modelling. I ran gravity load for the whole model (simple beam made of C3D8R). For Rigid body which is connected to the beam by surface-to-surface contact, I defined point mass using Interaction < Special <Point mass of 200 kg...
Dear all,
I have confusion wrt lever rule. In figure below, I want to find out LLDF using lever rule for exterior and interior girders on three-cell box girder.
for exterior girder one lane loaded, I found the fraction of truck loading multiplied to 1.2 for multi-presence factor. For two lane...
I am doing parametric study and need to compare it with some other approaches used for LLDF.
Shoot for the Moon, even if U miss, U still land among Stars!
The wheel load distribution factor equations from the AASHTO Standard Specification (AASHTO 1996) are called “S-over” equations, which is only dependent upon the girder spacing.
Shoot for the Moon, even if U miss, U still land among Stars!
Dear Bridge engs,
I am comparing the various methods used in the practice for calculation of live load distribution factor (LLDF) for various load effects. Please share your approach and the limitation if any that you faced.
Also, if someone has S-over equations, I'd be grateful to share it...
What is the element you used? It must be frame element else you cannot assign hinge property. Ensure you have defined your material NL and set the solver to NL.
Shoot for the Moon, even if U miss, U still land among Stars!
You can manually select the participation ratio in each direction, when you input as 100% let's say in X direction (for lateral wind load), then the energy contribution from that direction will be fully 100 at the end.
Shoot for the Moon, even if U miss, U still land among Stars!
Mawb,
your confusing yourself, you need to know that rotating an element does not change its output; the manuals says in the direction of local axes. Have a look at below links which describe basic of outputs for stress (it is for SAP2000 but concept is same and easier description for you to...
I agree with you; because the purpose is to increase a known load (in my case a truck load) until collapse occurs (based on plastic and nonlinear formulation I defined). Actually, I am getting more accurate results when friction coefficient is set to <0.3 or is set to frictionless. In the...
I suggest you compare the theoretical results with frame elements (beam elements in Abaqus), there you get sense of local axes direction.
Also in your figure, why there is high intensity for SM2 near supports? Do the following to rectify your confusion:
redraw the model with normal axis system...
In your picture, moment should be about Y axis since it is transverse to the element, your vertical force (shear force) is in Z direction and axial force in X direction.
So now if you want to perfectly bend the element, then you need moment at two ends, namely you need moment in Y direction to...
Turn on local axes from ODB display option to know the direction; of course SM1 is about local axis 2
Shoot for the Moon, even if U miss, U still land among Stars!
I also believe I don't need to put 'penalty' method, instead choose 'friction-less'.
Since the purpose if loading to find collapse load, the patch load is stationary and modeled as rigid body, so putting friction of 1 or higher I found that increases the total load (which is reasonable as the...
Hi all,
I have some truck axle loading modelled as patch load as shown below to load a bridge. For interaction property, I used Tangential Behaviour which is affecting the results significantly.
I know that there would be some friction in reality when the vehicle tyre is on bridge (stationary...
Do you mean the +ve n -ve moment due to ML? Since the direction of ML is downward and also DL is in gravity direction, then it reduces safety; if I understand you correctly.
This is from AS 5100.7:2017 page 25 section 12.2
Shoot for the Moon, even if U miss, U still land among Stars!
Thanks for clarifications, so in case of moving load then it reduces safety.
Also does "site specific measurements" means that we've obtained the geometrical measurement from the site and did the DL calculation?
Shoot for the Moon, even if U miss, U still land among Stars!
Hi all,
Can someone explain to me what's the application of using load factors when safety increased or decreased. How we can determine if the dead load increases/decreases safety?
Besides, what 'site specific measurements' implies?
Cheers,
Shoot for the Moon, even if U miss, U still...
If someone has access to AASHTO LRFD-2012, can you please let me know what clauses state the statistical parameters for load effects as below:
Shoot for the Moon, even if U miss, U still land among Stars!
Many thanks for prompt reply; I followed your suggestion but the issue is that when I want to access the 'jobname.sta' file in command window, it says "the process cannot access the file because it is being used by another process". And when I open the file by Note++, it asks me to reload the...
