The summary of the truss design PDF

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The summary of the truss designAssignment 3Group :Group member:Di SunTongXu XieYuChen Shizihao anZheng Fang1. IntroductionThe goal of this project is to design a roof load-bearing truss for a warehouse in Sydney. In the design, we must consider the capacity and load-bearing capacity of the truss str...

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The summary of the truss design Assignment 3

Group :23 Group member: Di Sun TongXu Xie YuChen Shi zihao an Zheng Fang

1. Introduction The goal of this project is to design a roof load-bearing truss for a warehouse in Sydney. In the design, we must consider the capacity and load-bearing capacity of the truss structure. In addition, this summary will also describe some of the design structure and design ideas.

2. Design and assumptions 1. The location of the warehouse is required to be in Sydney, and the spacing of the truss structure is required to be 3m.The total length of the wooden truss is 25m, and the height of the truss must not exceed 4m 2. There is a crane on the truss, the position is uncertain, but the maximum load-bearing crane is 20KN (Q2) 3. Thickness can choose 35mm or 45mm 4. The length of wood must not exceed 6m 5. The required specifications for depth of thickness are 45, 70, 90, 120, 140, 170, 190, 220, 240, 270, 290, 315, 340, 365, 390 mm. 6. Consider the calculation and design of the roof (Q1) according to the standard AS 1170.1 (2002) 6. The design will also be calculated in accordance with the Ultimate Limit State (ULS) and Serviceability Limit State (SLS) standards 7.Based on the standard AS/NZS 1170.0 (2002), the design only considers two load cases (1.35G and 1.2G + 1.5Q) 8. ctually does not consider the impact of natural factors on the building (earthquake, typhoon, etc.) 9. Design does not consider links to external structures 10. The timber grades available for the truss are F11, F14, F17, F22, F27 and F34, and the design standards are based on AS 1170.1 (2002), AS/NZS 1170.0 (2002) and AS 1720.1 (2010) 11. Do not calculate the net area except the tolerance, we assume the tolerance is 0 mm size The specific structure requirements are shown in the following table

3. Design direction and cost calculation First, we set the tickness of the cross section of the wood to 45mm, select F17 for the wood, and plot the data to Microstarn for analysis, and input the obtained value into excel for comparison. In the second step, through the diagonal load-bearing comparison, in order to meet the data requirements, we gradually reduce the wood section to meet the design requirements. In the third step, we adjust the load-bearing capacity of the structure through the section of the bottom chord. Except for the top chord, the sections of other structures are all 35mm Fourth, we adjusted the overall load-bearing capacity by adjusting the number of wooden beams. In the final design, the bottom chord used 2 truss woods, and the other parts only used 3 truss woods.

Finally, optimize the cost of the project, and finally adjust the project design data.

Element

Dimension

Critical

Section

Capacity

L(mm)*b(mm)*d(mm)

load

Capacity

Ratio

Tension- Diagonal

3652*105(35*3)*220

112.8 kN

428.4 kN

26 %

CompressionDiagonal TensionBottomChord

3652*105(35*3)*220

68.7 kN

146.64 kN

68.4%

2083*90(45*2)*220

130.4 kN

336.6 kN

72%

BendingBottomChord CompressionTopChord Bending- TopChord

2083*90(45*2)*220

1.5kNm

19.4kNm

8%

2083*105(35*3)*220

229kN

273.54kN

83.7%

2083*105(35*3)*220

1.9kN.m

17.2kNm

11%

The result check: Combined Bending and Compression

Combined Bending and Tension

Out-of-plane

0.85

Safe

Minor Axis

0.8

Safe

In-plane

0.74

Safe

Major Axis

-0.4

Safe

5:Errors and Inconsistencies In the design of this truss structure, except for the bottom chord, three F17 hardwoods are used, and the bottom chord uses two F17 hardwoods. But this design ignores the weight and bearing of the nail, so this will cause errors. In the design, in order to ensure the safety of the structure, it will affect the cost, so the designer must ensure the balance of safety and cost, and give priority to safety. Therefore, the length of wood used in actual operation is higher than the designed length, which will

cause some cost waste....