Purlin Meets Construction Requirements
Purlin is a purlin roof system and wall structure of the main components, because of its large area of use, so the proportion of steel in the housing structure is also larger, so should pay attention to the design of reasonable choice of purlin form, and pay attention to the layout of Purlin. Experience shows that one of the effective measures to save the steel quantity of purlin is to enlarge the spacing of purlin and reduce the weight of roofing materials. In terms of the cross-section of Purlin, purlin are generally divided into real abdomen type, Purlin hollow type and truss type Purlin.
Purlin connection is installed on the roof and external wall structure column beam, the secondary purlin is used to connect the roofing plate and the outer wall Board on the foundation structure, the purlin are commonly used in modern steel structure design of the main structural components, 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. 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, Purlin 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, Purlin the diameter of the round steel is not less than 10mm, H-beam as a house purlin, have a better tolerance
Purlin processing base is mainly in Jiangsu Money Bridge, when the wind suction over the roof of the permanent load, according to the actual force calculation of the bar section.
1. The old houses were used to stir the rafters. When Purlin spans a large 6m, a diagonal bar and a rigid strut are arranged at the roof or eaves, Purlin 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, 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, Purlin 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, Purlin make the horizontal wood of the roof
1. Purlin is a horizontal part along the length of the roof, which is located on the main rafters, supports the secondary rafters, and according to the force characteristics, Purlin the purlin shall be calculated and designed according to the internal force of the Biaxial flexural members.
2, purlin in the analysis of internal forces.
For both wind and wind conditions.
Modern steel structures are widely used in c& #47.
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. Purlin 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, it is considered that the elastic Foundation beam can be calculated by the compression rod, Purlin the restrained action of the flange is regarded as the function of the elastic foundation beams, The cross section torsion and the lateral bending effect are equivalent to the lateral loads acting on the lower flange, and the structural requirements can also be used to simplify the calculation, such as setting up the bracing.