how to input loads on platform attached to tall column

Posted by: arunbabu

how to input loads on platform attached to tall column - 02/07/10 11:38 AM

hi.,

i am beginner to vessel design.i came across a adequacy check for an process column,where in there is possibility of piping supports(only forces no moments) modeled on platform.which means these loads are transferred to vessel indirectly.to check the anchor bolt design for these extra loads and moments (the loads acting on platform are eccentric to vessel centre line hence moments also act on vessel).

i want to know exactly which is the correct procedure:

1.i understand , the platform weight acts at cg of platform and moment due to this weight also included in anchor bolt design.hence i will calculate the exact moment of these extra loads and calculate the corresponding weight of platform to produce such moment and give it as weight in platform dialogue box.

2. i will calculate the moments give it as extra moments and forces from force and moment dialogue box.

please help me ,how actually pvelite considers platform in the analysis.and also let me know is there any way other than this for analysing these extra loads for adequacy check.

thanks in advance

arun

Posted by: Mandeep Singh

Re: how to input loads on platform attached to tall column - 02/22/10 05:51 PM

Arun,

When you input the platform, then its weight is transferred to the vessel and as the platform is offset, the vessel will also see the additional moment. You can see this moment in the Elements and Detail report.

To include the additional weight of the piping you can use "Weight/Piping Dialog". Specify it as an offset weight. This way the natural frequency calculations will consider the effect of the additional mass, weight will be correct and additional mass from the offset that you specify will also be considered.

There may be other ways to handle it too.