Beam-to-beam connection with one angle at the bottom (seat) and one angle at the top for restraint is commonly termed what type of connection?

Introduction / Context:Steel beam connections can be framed, seated, or moment-resisting. A common shear connection uses a bottom seat angle to support gravity load and a top angle (cleat) for stability.

Given Data / Assumptions:

• Connection uses a bottom angle (seat) carrying bearing.
• Top angle provides lateral restraint and simple shear transfer.
• No web stiffener under the seat is mentioned.

Concept / Approach:With a seat angle but no dedicated web stiffener plate under the beam reaction, the connection is termed an unstiffened seated connection. If a stiffener plate is provided in addition to a heavier seat, it becomes a stiffened seat. These are generally classified as simple (shear) connections, not moment-resisting.

Step-by-Step Solution:

Verification / Alternative check:Connection manuals show unstiffened seats adequate up to a certain reaction; larger reactions require a stiffened seat (web stiffener) to prevent local web crippling.

Why Other Options Are Wrong:“Stiffened seat” needs stiffeners; “moment-resisting” implies rigid end-plate or flange-plate connections; “generic seated connection” is imprecise.

Common Pitfalls:Overestimating moment capacity of simple seated connections; neglecting bolt slip and bearing checks at the top angle.

Final Answer:Unstiffened seated connection