4420x
003095
2019-09-03

Question

In a nodal point, several members are hinged. How many member end hinges have to be defined?


Answer:

If two members are hinged to each other, the corresponding hinge must be assigned to one of these members only.

In the case of three members that are all hinged, two of the three members will have the corresponding hinge.

In general, a completely hinged nodal point with any number on member ends has altogether one less member end hinge than the existing number of member ends:

Number of member ends: n

Number of member end hinges for completely hinged connection: n-1

If the number of member end hinges is less than n-1, the respective member ends are connected rigidly without a hinge.

Image 01 shows three variants of the main beam, to which a secondary beam is connected:

  1. Fully rigid connection → no member end hinge
  2. Partially hinged connection: The secondary beam is connected to the continuous rigid main beam by a hinge → one member end hinge
  3. Fully hinged connection: All three members are hinged to each other → two member end hinges
If too many member end hinges are assigned, calculation abort may be caused due to instability. Therefore, it is necessary to follow the rule described above.