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Purlin Is A Common Part Of Modern Steel Structure Building


The stress characteristics of purlin

Purlin is used to connect the roofing plate and the outer wall plate to the basic structure, and purlin are the main structural parts of modern steel structure design, which can be on and meet the construction requirements.

Alternate arrangement near lower flange. The bar drawing can be arranged within the height range of 1/3 webs of the upper flange of the distance purlin. Purlin Some constructional measures of purlin

When the purlin span is greater than 4m, the bar should be set across the middle position between the purlin, in order to take into account the two situations, in the area of wind load large or in the eaves and the ridge of the installation of the diagonal bar, or the bar and the diagonal bars are both tensile and pressure-bearing rigid rod.

Pull bar is usually made of round steel, the diameter of the round steel is not less than 10mm, Purlin H-beam as a house purlin, have a better tolerance

The domestic purlin processing base is mainly in Jiangsu Money Bridge, more well-known manufacturers have hundred Ann Light steel structure Products co., Ltd., Wuxi Hengchang Steel Co., Ltd.

When the wind suction exceeds the permanent load of the roof, the drawing section is calculated by the actual force.

1. The old houses were used to stir the rafters. When Purlin spans a large 6m, Purlin a diagonal bar and a rigid strut are arranged at the roof or eaves, and the transverse force is pointed opposite. At this point, the diagonal bar of the Z-shaped steel bar needs to be set at the ridge, while the edge of the steel Purlin is located in the eaves, should be in the Purlin span three points at each set a pull bar.

When the flange under the wind suction under pressure, the roof should use the self tapping screws directly connected with purlin, Purlin the pull bar should be located near the lower flange.

The function of the strip is to prevent the lateral deformation and torsion of purlin and provide an intermediate fulcrum in the direction of the x-axis. The force of the intermediate fulcrum needs to be transmitted to the larger member of the stiffness for this reason, the calculation of internal force is related to the arrangement of the drawing bar, and the qx of the horizontal load is calculated by the two-span or three-span continuous beam under the action of a two-way drawing.

3. The drawing arrangement should consider the influence of wind load, make the roof of the horizontal wood 1, purlin is along the length of the roof distribution level parts, located on the main rafters, Purlin supporting the secondary roof rafters, according to the force characteristics, Purlin should be based on two-way flexural members of internal force calculation and section design

Purlin has the main purlin and the second Purlin, is one of the main components of the House, also called the truss son

What are the design features of Purlin?

(1) Purlin is a thin-walled member, which may lose local stability and produce buckling in the force state, but can still be loaded after buckling (using the film effect, i.e. the tension field). In the design, the strength is calculated by using the effective section method.

(2) The overall stability calculation of purlin is divided into two kinds of situations:

A. Under the action of the wind pressure, the general pressure steel plate (the condition is sufficient shear parts) and the compression zone set by the Purlin tension bar can play a lateral restraint role.

B. Under the action of wind suction, the lower flange under pressure (the continuous setting of purlin under the action of wind pressure is similar), the Force state is similar to the elastic Foundation beam, Purlin it is considered that the elastic Foundation beam can be calculated by the compression rod, the restrained action of the flange is regarded as the function of the elastic foundation beams, The cross section torsion and lateral bending effect are equivalent to the lateral loads acting on the lower flange to simplify the calculation. Purlin can also be used in construction requirements, such as setting the corner.