Portal frame connections Portal frame haunch

Portal Frame

27 Portal frame haunch

(a) Assume the number and type of bolts required at 1 and 2 (see Fig. 27) to resist the factored bending moment, and locate them to obtain the maximum lever arm.

(b) Using the force distribution shown in Fig. 19, calculate the resistance moment. If this is less than the applied moment increase the number and/or size of bolts.

(c) Check the thickness of the end plate required to resist the bending moments caused by the bolt tension. Double-curvature bending of the plates may be assumed since bolts occur on both sides of the web.

(d) Check that the sum of the horizontal bolt forces at 1 and 2 (see Fig. 27) can be resisted in shear by the stanchion.

(e) Check the bending stresses in the stanchion flange caused by the bolt tension; normally local stiffener will need to be added.

(f) Calculate the additional bolts required at 3 (see Fig. 27) to resist the applied vertical shear by checking the single shear capacity of the bolts and the bearing on the end plate and on the stanchion flange.

(g) Check for reversal of moment due to wind, as this may govern the design of bolts (3 on Fig. 27) and of the stiffners.

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Responses

  • Mafalda
    How to calculate haunch dimensions for portal frames?
    6 years ago

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