Study on Bearing Performance of Typical Fixed Metal Fasteners in Glasshouses of Beijing Botanical Garden

The introduction point-type supporting glass structure is a new type of building structure which has been widely used in recent years. It has the advantages of elegant appearance, good permeability, etc. The Beijing Botanical Garden uses this structure in the greenhouse, which uses metal connectors to connect the support system and the glass plate in order to properly evaluate the glass room point.

The introduction point-type supporting glass structure is a new type of building structure which has been widely used in recent years. The utility model has the advantages of elegant appearance, good permeability and the like. The Beijing Botanical Garden uses the structure of the glass in the greenhouse, and uses the metal connecting member to connect the supporting system and the glass plate into one body in order to reasonably evaluate the bearing performance of the glass room point supporting glass structure. .研究 Study the bearing capacity of metal connectors.

The gold connector is divided into two parts: a gold fastener and a support member (claw member). The geometrical dimensions of the finite element transverse 9 typical fixed floating head and countersunk fasteners are as shown in the figure. This geometric model divides the mesh to generate a finite element model. Considering the symmetry of the model, only the 1/2 model is established. As shown in the actual project, the screw of the fastener is fastened to the support member to simulate the real In the case, a solid end constraint is applied to the screw end of the model, and a symmetrical constraint is applied to the cross section. Fasteners may be subjected to different loading effects such as pulling, pressing, shearing, shearing and shearing, and compression and shearing. Therefore, loads are applied to different parts of the model to simulate different loads. When the fastener is pulled. An upward compressive stress shall be applied to the lower surface of the upper pad: when the fastener is pressed, a downward compressive stress shall be applied to the upper surface of the lower pad; if the fastener is sheared, the inner shaft shall be Apply a nodal force on one side. The fastener material is made of stainless steel lCrl8Ni9, and the mechanical properties and physical properties of the chamber are calculated only in the online elastic stage.

The finite element type of typical fixed fasteners (a) fixed to the floating head; (b to the countersunk head 2 typical fixed gold fasteners analysis 2.1 fixed floating head fasteners bearing performance when fixed floating head fastening When the piece is subjected to load, it is possible to reach the maximum value of vonMiscs stress at three key points: a. the upper plate and the mast are connected; b. the joint between the mother and the screw: c. the end of the screw. The stress values ​​at these critical points determine the control points for the bearing capacity.

Since the model is only calculated in the online elastic phase, when the fastener is only subjected to tensile force, pressure or shearing force, only the unit force can be applied to the model for analysis without the need to load the w. fixed floating head fastener. The vonMiscs stress values ​​for each key point of the tensile load capacity model are shown in Table 1.

Table 1 Calculated value of vonMiscs stress and theoretical value / MPa stress calculated value of the stress value of the fixed floating head firmware when tensioned, the stress concentration factor 〃c / 1 screw end part of the upper end of the screw and the screw The table at the junction of the mast indicates when the fastener is pulled. The stress concentration of the upper pad and the screw is the most serious. The tensile bearing capacity of the fixed floating head fastener is controlled by the concentrated stress at the joint between the upper pad and the mast. The yield strength of stainless steel is 196N/rranM. Therefore, the tensile load capacity of the fixed floating head fastener is 3.16kN. Calculating the von Mises stress and the theoretical vonMises stress column at various key points of the compression bearing performance model of the fixed floating head fastener In Table 2: Table 2 calculated values ​​of vonMises stress and theoretical value / MPa stress calculation value of each key point when the floating head fastener is pressed. It is known from the calculation results that the tensile load capacity of the fixed floating head fastener is less than solid. The countersunk fastener is attached, and the former has greater compressive and shear bearing capacity than the latter. Therefore, from the standpoint of load bearing performance, if the fastener is used to suspend the glass plate, the countersunk fastener should be used: if it is used to support the glass plate or bear the weight of the wall glass, it should be selected. Floating head fasteners.

The stress concentration factors of the key points given in this paper are only for the general situation of the typical fixed fasteners in the glass greenhouse of Beijing Botanical Garden. It is necessary to further study the factors affecting the stress concentration factor at key points, so formula (1)(9) The value of the stress concentration factor will vary.

The calculation results of the theoretical formula and the finite element analysis also require experimental testing, which is also an in-depth work in the future.

Steel Drag Chain (Steel Cable Drag Chain), commonly used in machine tools machinery such as cable, tubing, the trachea, water pipe, air duct, traction and protection.Now the steel drag chain (Steel Cable Drag Chainhas been widely used in machine tools, to protect the cable also make machine overall looks more beautiful.

steel drag chain


I.         TL series steel drag chains (TL series steel cable drag chains)

TL series drag chains are mainly consisting of chain plate (top quality stainless steel with chromium plated), supporing board (extruded aluminum alloy) and pinshaft (alloy), etc. There is no relative motion between the cables/ rubber hoses and the drag chains, giving no deforming or twists. The chromium plated chain board has very nice-looking appearance and has very rational construction and flexible and high strength. It is reliable and easy to operate, install, dismantal or assemble. It is worthwhile mentioning that the anti-wearing performance has been improved greatly due to wear resistant material and alloy pinshaft are used. The product is flexible to bending and has low resistance, giving low noises. It can be used for a very long period of time without any deformation or hanging down.

The product is nice-looking, which makes the machine tool unit nicer looking as a whole and makes the machine tools and machineries more competitive in the international market.

1.     The drag chain can adapt to max moving speed of 40m/sec.

2.     When at the max moving speed, the sound pressure of noises shall not be greater than 68 db.

3.     The service life of the drag chain shall not be less than 1 million times (reciprocating).

Drag chains with 3 chain board:

One or more drag chain boards can be installed on a wider drag chain, because the max length of the supporting board is 600mm-650mm. This arrangement can also improve the stability of the narrower chains. In this way, the conduit and the cables can be separated from one another by a third chain board.

Elastic status for hydraulic pipes:

Note that the pressure of a hydraulic pipe may extend or contract downward, so the elasticity should be taken into consideration, especially under high pressure or with long length.

II.       TLG series steel drag chains (TLG series steel  cable drag chains)

There are TLG separate type and TLG frame type.

The TLG type drag chains are suitable for installing a large quantity and heavy duty of cables and oil pipes which allow suspending installation (supporting is not allowed) and is lengthy. The supporting plate can be made according to the user`s requirements. It is suitable for machine tools and moving machines. Their bent radius ranges from 50-600mm and the chain`s height is from 35 to 150mm. Users can make a free selection of them.

The TLG type drag chain has a max travel range of 32 meters and is suitable for all kinds of transmissions. It can freely be made longer or shorter. In addition, the bend radius can be changed by changing the pinshaft.

The width of the supporting board is from 150mm to 600mm. The distance between the holes is 5mm.

The height of the supporting board depends on the max outside diameter of the cables. When the machine tool is working in the highest speed and if the max width of the drag chain is longer than 300mm with the chain`s length longer than 4m, one size larger than normal should be selected just out of consideration of safety.

The bend radius should be selected according to the max diameter of a cable and should be 10 times of the diameter of the cable used. The bend radius can be selected as 50-600mm according to the given table. Small radius should be selected for those ones with small travel range.

Drag chain length=1/2 travel range + 4 bend radius, this is only used for the fixed connection which is located at the middle point of the travel range.

The fexation of the drag chains can be done according to the location of the machine tools. The angle steel can be put in the outer or the inner, in other words, in the inner side of the chains or in the outer side. In common cases, it is in the inner side of the chains and face towards outside.

Main parameters & demensions for steel type drag chains (steel cable type drag chains)

type

Bending radius (mm)

pitch

a

c

d

e

f

g

h

k

The length of the overhead (m)

Load

(kg/m)

Weight per meter

L=100mm

TLG75

100/150/200/250/300

75

31

50

8

4

30

12

9

15

4

3

4

10

15

10

5.00

4.90

5.50

 

TLG100

150/200/205/300/400

100

49

75

10

4

50

17

11

21

6

4

6

15

20

15

9.30

9.10

10.00

TLG125

200/250/300/400/500

125

68

100

14

4

70

22

13

28

8

6

8

30

20

30

18.40

18.10

19.30

TLG180

250/300/400/500/600

180

118

150

14

6

115

26

13

32

15

30

25


Example for an order: Travel 11.2m, Bending radius 300mm, 3 Cable diameter 48, 3 Cable diameter 28, 2 Houses diameter 36

Type

Radius

Length

Width of support board

Mode fixing

Mode of Installation

TLG75

300

6875

350

D/E

S

The TLG type aluminium alloy drag chains are different from the ordinary ones. The can made by using fixed aluminiu shape materials to meet the needs of the users. The width of the supporting board can be 12mm. When operating under high operating speed and high travel speed, the drag chains can be separated from one another so as to ensure the cables being protected in a very safe condition.

TLG aluminum alloy type is the only solution to the larger size chains. The supporting boards can be made according to the requirements of the users. Thanks to the strong construction, the width of the supporting board can be 1200mm.

TLG plastic spacing straps can moved and adjusted in position freely. See figure for details. If cables in many different specifications, you may select this economic device. 


Steel Cable Drag Chain

Steel Cable Drag Chain,Stainless Steel Cable Drag Chain,Aluminium Steel Cable Drag Chain,Stainless Track Carrier Drag Chain, Stainless Carrier Drag Chain

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