You are able to specify spring connection and assign it to a lateral beam. This type of connection is also referred to as moment connection which means that it only transfers moment between a beam and a column.

A connection spring can be assigned to either the left or right end of the beam. If values are not assigned to a particular end ("No Spring"), the Standard fixity assignments is used.

A spring connection configuration can be conceptually idealized as in the following figure: two infinitely rigid plates are defined; one is attached to the column face and the other is on the beam and these plates are connected to each other through a rotational spring with stiffness k_r.

Spring Connection Idealization

If the spring is infinitely stiff, connection rotation, θ_r , is zero. This means that two rigid plates are attached together and there is no relative rotation between them. This represents a fixed end condition for the beam and there is full moment transfer from beam to column or vice versa. On the other hand, θ_r is substantially large if k_r is almost zero. This represents a pined end condition for the beam (no moment transfer between beam and column). These two extremes bound the range of the response of the connection. Any finite number of k_r yields connection rotation within this range.

Connection stiffness (k_r ) is defined in terms of moment per radian and this type of connection is only applicable for major axis bending. The term k_r can be defined either as a percentage of beam major axis bending stiffness (i.e., 4EI/I_maj) or it can be directly entered by the engineer.