Design considerations

Determine load conditions: Structures will be subject to tension, compression, torsion, and bending. These loads must be calculated under service conditions. Locations of critical loads must be determined and the structure designed to handle the loads efficiently. Careful designers will locate joints away from high-stress areas when possible.

Consider producibility:The most elegant design is useless if it cannot be made efficiently. Welders cannot always fabricate what designers think up. Designers should spend time in the shop and consult foremen or manufacturing engineers during design to become familiar with the challenges of translating drawings into products.

Optimize layout: When drawing the preliminary design, engineers should plan layout to reduce waste when the pieces are cut from plate. Preformed beams, channels, and tubes also may reduce costs without sacrificing quality.

Consider using standard sections and forms: Preformed sections and forms should be used whenever possible. Specifying standard sections for welding is usually cheaper than welding many individual parts. In particular, specifying bent components is preferable to making welded corners.

Select weld-joint design: There are five basic types of joints: butt joints, corner joints, T-joints, lap joints, and edge joints. In addition, the American Welding Society recognizes about 80 different types of welding and joining processes. Each process has its own characteristics and capabilities, so joint design must be suitable for the desired welding process. In addition, the joint design will affect access to the weld.