Learning Goal: Part B- Check shear stress To design a plate girder for bending, confirm the shear stress limit, and determine the required weld stress limit for the web/flange joints. Choose a flange width bf = 14 in. Once the girder has been designed for bending, check the maximum shear stress to verify that the section is adequate. What is the maximum shear stress for the girder? Beams support loads perpendicular to their long axes. For beams with long spans, the bending loads typically cause the highest stresses, so the beam section is designed based on the maximum moment. Then the chosen design can be checked for adequate shear stress limit. If the beam has a short span and large loads, then the shear stress may control the design. Express your answer with appropriate units to three significant figures. > View Available Hint(s) To select a beam section based on the maximum moment, the required section Mmax HA ? modulus can be determined by Sreg = For preformed shapes, the Oallow section modulus is often tabulated with the section properties. For built-up Value Units shapes, the dimensions need to be chosen so that -> Sreg Submit With built-up beams, it is also necessary to design the connection between the pieces. The welds or fasteners must be sized so that they can support the longitudinal shear loads. The shear load supported by the weld can be found VQ It using the shear formula T= Part C - Minimum weld strength The plate girder is constructed by using a fillet weld on both sides of the web to connect each flange (Figure 2). These welds must support the longitudinal shear stress between the we and flange so that the girder can act as a single structural unit. What is the required weld strength per unit length? Use bf = 14 in. as in Part B and assume that each weld supports ha Figure 2 of 2> the load. kip to three significant figures. in. Express your answer in I • View Available Hint(s) V AEO t ? vec kip weld strength = in