Question:

There are various categories listed in the SACS Physical Element which I don't understand the meaning. What does it mean with Off-line and on-line member?

Answer:

This information can be found in Precede manual from here: SACS Executive >Support > SACS Help > SACS Precede > Modeling > Misc > Physical Element

Straight member (off-line):

A non-continuous member made up of a set of ordered structural members which has a break at every intermediate joint that has a through member passing through it. The offset ends of all the structural members form a straight line. The member offsets at all intermediate joints are recomputed during validation to ensure that the line is straight.

Straight member (on-line):

A non-continuous member made up of a set of ordered structural members which has a break at every intermediate joint that has a through member passing through it. The offset ends of the continuous member and all intermediate joints along the member form a straight line. The member ends at all intermediate joints may only have offsets that lie along the length of the line. The intermediate joint locations are recomputed during validation to ensure that the line is straight.

Through member (off-line):

A continuous member made up of a set of ordered structural members. The offset ends of all structural members form a straight line. The member offsets at all intermediate joints are recomputed during validation to ensure that the line is straight.

Through member (on-line):

A continuous member made up of a set of ordered structural members. The offset ends of the continuous member and all intermediate joints along the member form a straight line. The member ends at all intermediate joints may not have offsets. The intermediate joint locations are recomputed during validation to ensure that the line is straight.

Summary:

On-line means that all intermediate joints of the straight or through member lie on the line defining the offset member.  Off-line means that all intermediate joints of the straight or through member lie between the two end joints and the members are offset at the intermediate joint to the line defining the offset member.