The influence of the column on the steel structure space frame

The influence of the column on the steel structure space frame is manifested in that if the rigidity of the column is large and the horizontal displacement is restricted by the connection node of the space frame and the column, the temperature stress of the space frame cannot be released, and the pressure of the upper chord of the space frame under the action of temperature Stress must be fully considered for safety.

The calculated length mainly depends on the support system of the column and the horizontal rigidity of the space frame. In theory, if the support system is sufficiently rigid, the horizontal rigidity of the space frame can generally be seen from the infinity of the column (except for the narrow and long), and the horizontal stiffness of the space frame can be calculated. From experience, the horizontal rigidity of the space frame (calculated with the spacing between the columns as the span) is greater than 5 times the sum of the lateral stiffness of the supporting columns. It can be considered that the horizontal rigidity of the space frame is large enough.

Movement can be restricted (either there is support outside the plane or rigidly connected beams, the calculated length can be calculated), and the support system uses a space frame to ensure the stability of other columns in the plane. At this time, the calculated length can be calculated as no side shift. Fixed hinge and beam-column articulation are two concepts. The connection between the space frame and the column is generally articulated, which is usually calculated on the safe side.

The strong and weak support concept proposed by the code is generally a prerequisite for the basic rigid floor or rigid horizontal support. It not only requires a certain rigidity and strength required for the support between the steel space frame columns but also the horizontal support system must be strong to ensure the transmission of horizontal force.