Lbycvt3 Case Study 2

De La Salle UniversityCivil Engineering Department

LBYCVT3

Case Study 2:Modelling 3D Steel Roof Truss System Using

SAP2000

Submitted by:Janssen Valbuena

Eldrich KawGroup #11

EH1

ABSTRACT: The study of this paper is to analyse a structure using SAP2000. SAP2000 can analyse different structures in 3D with different load cases. SAP2000 can give results such as axial stress, torsion stress and deformation. For our study, the structure we are analysing is 3D Steel Roof Truss System.

I. INTRODUCTION

A roof truss system is a rigid, strong frame work made up of different materials such as steel or wood. The members are usually fastened and held together by metal connector plates. This framework accounts for the shape the roof and supports the roofing materials. Roof trusses are designed according to ancient geometric principles. Many of the bridges you drive over were designed using the same principles. Figure 1 shows different types of truss that is used in some structural applications.

In our case study, the model is a 3D steel roof truss system. The material we used in our study is a steel pipe with a diameter of 0.11 meter and has a length of 5 meter. The roof truss system in our study is supported by a pinned support.

Figure 1 Common types of truss

II. STRUCTURAL MODEL AND PLANS

Figure 2.1 Perspective Plan of Building

Figure 2.2 and 2.3- roof plan and detailed structural plan of the truss system

III. METHODOLOGY

Create a New Model

The model of this case study is a 3D Steel Roof Truss System. To create a model, we choose to select grid only since it is the simplest way to start modelling a truss system.

Define/Edit Grids and Floors

To start modelling our 3D Steel Roof Truss System, we define first the number of grid in each axis and its spacing. The spacing is base on the dimension of the truss section. Figure 3.2 shows the ordinate of the grid in each exis. Figure 3.3 shows the output of the grid lines.

Figure 3.2

Figure 3.3

Define Materials

Figure 3. shows the different properties of the material. The type of material is steel and different properties like modulus of elasticity and poission’s ratio can be modified using this menu.

Figure 3.4

Define sections

Figure 3. shows the dimension of the section. The type of section is a pipe and it has an outside diameter of 0.11m and wall thickness of 0.017m.

Figure 3.5

Draw Members

Figure 3.6 shows that frame members of the 3D Steel Roof Truss System are drawn.

Figure 3.7 shows that other members of the 3D Steel Roof Truss System are drawn.

Different views showing the model of the structure

Figure 3.8 shows the 3D view of the model.

Figure 3.9 shows the side view of the model.

Figure 3.10 shows the top view of the model.

Generate Load Cases

Figure 3.11 Wind load was generated in our load case

Assign Loads

Figure 3.12 A concentrated load of 10 kN was assigned to different joints of our structure

Design the Members

Figure 3.14 shows the design and checking of the structure

IV. CONCLUSION

In our study, we were able to successfully model the steel roof truss system with SAP2000. SAP2000 is more complicated to use than GRASP because it analyses structures in 3D and can give a more sophisticated data. It is also more complete than GRASP in a lot of aspect. SAP2000 is a more suitable choice to use in practice because it can analyse structures with different truss system in each level and can show data such as torsion that is not present in GRASP.

REFERENCES:

http://www.trusssystemsinc.com/index.php?option=com_content&view=article&id=49&Itemid=57http://mysite.dlsu.edu.ph/faculty/oretaa/Publicationshttp://www.scribd.com/doc/132759040/SAP-Seminar-Session-01-Modelling-a-Truss