Joint can length override command in SACS


Q:

How does the joint can length override option work in SACS?

 

R.

User needs to select BRCOVR command in joint can input file.

With that, the overall algorithm of SACS should be understood to cater the proper use of the feature.

Let us walk through the method.

Assume a Tee joint with O being the common joint for Brace OB and Chord AZ. In the chord till OP and OQ, we have a thickened can. See the snap below for the overall geometry.

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Case 1: I have modelled OA as a single member with OP and PA as its segments. No joint at P. SACS will look for the next joint from the common joint to define the Chord member. Here, this happens to be joint A. So, SACS will consider the OA member as chord. In the chord geometry, the OP segment happens to be a thicker CAN and SACS will consider the API RP 2A Equation 4.3-4 for this segment.

Case2: I have modelled OA with introduction of joint P along the length. Here my OP member has higher thickness and OA member has lower thickness. SACS will look for the next joint from the common joint to define the Chord member. In this case, the OP member becomes the chord for the joint check. Since there is no thickness variation along OP there is no thicken CAN for SACS to consider. SACS will not use the API RP 2A Equation 4.3-4 here.