Industrial sectional doors are the most durable and longest lasting doors to ensure circulation at the areas of the factory entrance and exit of goods, loading and unloading areas.
The body of sectional door is forming by 40 mm sandwich panels. These panels provides sound and heat insulation due to the intense doped polyurethane insulation was injected between galvanized steel sheet. (50 kg/m3).
Industrial sectional door systems provide space-saving with opening parallel to the ceiling.Any opening can be used clearly . and produces in accordance with the transition range and the height in the factory buildings or warehouses.
Doors is working sliding by be the most appropriate the gap between the top level of the gate with a ceiling height within the side rasils. The door can be mounted in different ways according to the gap distance (standard, low, highlift and vertical track systems).
Industrial sectional doors can easily be opened automaticly by 230-380 V-AC/50 Hz electric motor or manualy thanks to torsion spring system that balances the weight of the door.The galvanized springs are made to be durable of 25.000 door cycles.Motor with emergency chain All the drive systems have a mechanical back-up system fitted to the reduction gearbox of the electric motor, so that the sectional door can be opened if the power fails. The reduction gearbox can then be powered using the chain.
Industrial Sectional Door,Industrial Overhead Sectional Door,Industrial Warehouse Sectional Door,Industrial Garage Interior Sectional Door Shenzhen Hongfa Automatic Door Co., Ltd. , https://www.hongfadoor.com
Application and superiority analysis of standard parts in buildings
Reinforced concrete shear walls are the primary lateral load-resisting systems in high-rise buildings. Performing nonlinear analysis of these structures using finite element methods can be computationally intensive. To address this, various macroelement models have been developed to achieve acceptable accuracy with reduced computational effort. In a shear wall macroelement model composed of springs, the vertical spring stiffness is determined based on the uniaxial behavior of concrete, which is relatively straightforward. However, the horizontal shear spring stiffness is more complex. Since the introduction of the Modified Compression Field Theory (MCFT) by Vecchio and Collins, shear stiffness has typically been calculated using coordinate transformation and MCFT. This requires defining boundary conditions for the macroelement. The most common assumption is that the horizontal stress, Rx, equals zero. However, since the corresponding strain, Ex, is unknown, an iterative approach is usually needed. In this study, Ex = 0 is used as the boundary condition, eliminating the need for iteration when applying the constitutive relationship. Qualitative analysis suggests that areas near the edges of the shear wall are closer to free boundaries, where Rx = 0 is more appropriate. Additionally, Ex = 0 aligns with the rigid horizontal rod assumption in the macroelement. While determining elastic strain generally requires iteration, this paper proposes using MCFT under a full-strain principal axis system, avoiding iteration. It is shown that the two approaches yield equivalent results when solving the total stiffness equation iteratively.
A new six-degree-of-freedom rigid-rod spring element is introduced, incorporating a shear wall macroelement model that accounts for shear warping in the cross-section. Several cases are analyzed to evaluate the overall accuracy while keeping the computational cost minimal. It is observed that placing the two vertical springs at Gauss points improves the accuracy of internal forces compared to other positions, such as between nodes, especially when the stress distribution can be approximated by a quadratic polynomial over the element span. The method also achieves equivalent accuracy with fewer calculations compared to distributed elements along the x-direction.
An example compares different shear spring superposition techniques with the two-axis constitutive model of concrete, conducting an elastoplastic pushover analysis on a medium-to-high-rise shear wall under lateral loading. The additional virtual spring method is used to handle stiffness issues. The concrete strength grade is C25, and the dimensions, reinforcement, and mesh division are provided. The axial compression ratio is 0.13. The lateral load-displacement hysteresis loop is compared with experimental data, and the relationship between average shear stress at two Gauss points and shear strain is examined. Modes 1P1 and 1P2 represent shear springs with Ex = 0 and the two-axis constitutive relation based on full-strain and elastic-strain principal axes, respectively. Modes 2P1 and 2P2 use Rx = 0, with similar constitutive relations.
Conclusion: (1) The shear strain relationships from MCFT based on full-strain and elastic-strain principal axes are equivalent when using an iterative method. (2) The shear capacity from different boundary conditions (Ex = 0 vs. Rx = 0) is similar, and pre-yield stiffness is comparable, but post-yield behavior differs significantly. (3) Different treatment methods have minimal impact on the bearing capacity and stiffness of medium-to-high-rise shear walls. Therefore, to reduce computation without sacrificing overall accuracy, it is recommended to use Ex = 0 and the full-strain principal axis system. (4) Assembling the shear wall macroelement model using bidirectional basic macrocells reflects the shear deformation of the cross-section and provides a detailed distribution of shear stress within the section.