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### Author Topic: Determining Strength and Buckling Design-to Loads  (Read 3073 times)

#### James

• Posts: 117
•
##### Determining Strength and Buckling Design-to Loads
« on: December 10, 2009, 09:01:54 AM »
Question From OS Support Ticket System:

How can I have design to loads for strength greater than for buckling ? I don't see where the -21962.2 can come from in the attached picture. None of the 25 loadcases show this value.

« Last Edit: December 10, 2009, 09:05:35 AM by James »

#### James

• Posts: 117
•
##### Re: Determining Strength and Buckling Design-to Loads
« Reply #1 on: December 10, 2009, 09:06:39 AM »
The design-to loads for strength are based on your selected statistical loading method. From your picture I see you have selected the 2-sigma approach. HyperSizer is taking the average element based load "C-Average" and subtracting 2 times the standard deviation "C-Std Dev". This gives you the unfactored strength-based load for the component. HyperSizer is performing the same calculation for the tension elements as well.

Strength based Load = (C-Average)-(2*C-Std Dev)
or
(T-Average)+(2*T-Std Dev)

To get the factored loads simply multiply the unfactored by the ultimate load factor (1.4).

Again to obtain the factored buckling load, simply multiply by the mechanical ultimate factor.