Grid support selection

With the development of the economy, the construction of large-scale grid structures, especially the large-scale and complex reticulated shell structure, has caused stringent temperature-induced rod contraction, structural resistance to wind stability, and seismic isolation and vibration isolation performance requirements. The design usually chooses to release the internal stress of the structural node, or design the structural node stiffness to solve the above problem.

This makes the structure design more and more use the support to achieve the above-mentioned purpose, using the rotation and displacement of the support to improve the stress condition of the node. The following briefly describes the selection of the product of the grid support bearing based on the design principle and the current status of the support.

The spherical bearing consists of an upper seat plate, a lower seat plate, a convex middle plate and two different shapes of Teflon plates. The middle of the lower seat plate is a concave spherical surface, corresponding to the convex middle plate, with a curved PTFE plate lined between the two, and the sliding of the spherical surface meets the rotation of the beam end; the stainless steel plate and the middle steel plate on the upper seat plate Another PTFE plate on the second sliding surface composes the telescopic displacement of the upper and lower structures caused by the temperature difference.

The spherical hinge support is provided with four flanges on the inner cylindrical wall of the support plate on the ball bearing, and four flanges on the upper edge of the base. When the assembly is assembled, the upper cover plate is rotated into the base and then rotated. 45. By engaging the upper cover plate with the flange of the base, the internal force can be directly transmitted between the upper cover plate and the base plate to prevent the various parts of the spherical support frame from being separated from each other.

Damping seismic isolation ball bearings Common ball bearings, due to the use of PTFE plate and mirror stainless steel plate as a horizontal sliding surface, and the friction coefficient between the two plates is quite small, so within a certain range of displacement The horizontal stiffness is very small and it can be considered as an isolating device.

The shock-absorbing and shock-isolation ball bearing is a type of bearing composed of an ordinary spherical bearing and a damper. On the one hand, the damper can increase the horizontal stiffness, and on the other hand it has a certain energy consumption characteristic. Damper can be divided into dry friction damper, fluid damper, material damper and slip damper according to different energy consumption mechanisms. Due to the size limitation of the oil damper, it is usually separated from the ball bearing. The use of material dampers is usually integrated with ball bearings. In the market, it can be seen that the dampers used to absorb shock-isolated ball bearings include high damping rubber dampers, multi-leaf spring dampers, lead extrusion or pure shear damper bearings. The following factors should be considered:

(1) Maximum and minimum vertical use loads and horizontal load use and the order in which they are applied;

(2) The maximum and minimum angles required for structure and construction, and the control of horizontal displacement;

(3) The permitted arrangement of the bearings;

(4) Limits for brackets, movable supports, and temporary devices.

Bearing design After determining the load conditions and size limitations of the bearing, the design of the bearing mainly considers the following factors:

(1) Determine the horizontal projected radius of the PTFE spherical convex plate and the radius of curvature of the curved surface according to the load of the support and the strength of the PTFE plate;

(2) Determine the thickness and roughness of the stainless steel plate according to the requirements of the specification;

(3) Determine the size of the spherical cap liner and the lower holder plate according to the specifications;

(4) If necessary, design the damper.

More introduction: http://jingongzhongxin.cn.made-in-china.com/