Purpose
Because of the rigidity of a truss shape, it is not difficult to find the familiar triangles in many structures. Designers must accurately determine how much force occurs at locations of a truss design. The designer may change the material, the amount of material, or the number of members in a truss in order to make a design safer or more efficient. The calculations for determining truss forces are also a good basis for calculating forces for many other systems.

Equipment
Straight edge
Calculator

Procedure
In this activity you will make changes to given trusses to make them statically determinate. You will then solve for the outside forces and forces at each pinned connection of trusses.

Static Determinacy
It is important to know that a truss is statically determinate before attempting to solve for the internal forces. If the truss is statically indeterminate, then you will not be able to solve for all of the forces.

The trusses 1, 2, and 3 are statically indeterminate based on the formula 2J = M + R. Use the formula to demonstrate that each truss is statically indeterminate, then sketch a solution that would result in the truss being statically determinate. Remember when you sketch solutions that each should retain triangular shapes in order to remain rigid. J = Number of joints | |

M = Number of members| |
R = Number of reactions within a support| 0r |

*
*
| 2J=M+R(2*40=(5+4)8≠9|

| 2J+ M + R(2*4)=(3+4)8≠7|

| 2J=M+R(2*4)=(5+4)8≠9|

Solving Statically Determinate Trusses
Use the method below to calculate the forces occurring at each pinned connection.

Draw a free body diagram of the entire truss. Label applied forces, known dimensions, and replace supports with labeled reaction forces. Sum the moments occurring about one or more pinned support(s) to solve for reaction forces at supports. There may be occasions when this will not solve any...

...Objective
The objective of the project is to build a truss that would be able to take a specific amount of downward force remarkably with respect to the weight of the truss itself, i.e. to construct a truss that would hold a relatively high efficiency score. And construct the bridge in such a way to as to keep the deflection of the structure at minimal.
Introduction
First of all, what is a truss? In an engineering view, atruss is a structure that is made up of series of triangular unit made of straight members that are connected at junctions known as nodes. External forces created by bodies known as loads, are often placed on areas of the structures which then creates internal forces in the members in form of either a Tensile Force or a Compressive Force. The practical analysis was carried out to help better our understanding on the theories behind the behaviour of a truss under different circumstances.
Analysis
A Pratt truss illustrating the arrangement of the bars
By calculation
The length of the horizontal member is 99.4m
The height of the bridge is 20m.
And the diagonal members are all 23.6m
The distance between the two sides (floor Beam) was 16m.
Materials
Today, bridges can be of the span, arch, or suspension type. Materials used throughout history include wood, masonry, cast iron, wrought iron, concrete, steel, reinforced concrete, alloy and...

...Technology |
Planar Truss |
Project 1 |
Engineering Design III – E 231 – Section D – Group 7 | |
11/9/2010 |
“I pledge my honor that I have abided by the Stevens Honor System.” |
Abstract
The planar truss was constructed according to the requirements of the E231 by attempting to support a large load. Three designs were constructed to fit the necessary requirements. The design with the largest strength to weight ratio was chosen. The truss was then constructed using square brass tubing and then tested for the strength by applying a vertical load with a buster. The goal of the project is to make a truss to hold the most load out of the whole class.
Table of Contents
Abstract i
Introduction 1
Discussion 2
Design 2
Overview of design process 2
TrussDesign Details with Alternative Designs 3
Design Analysis Summary 6
Calcuations of weakest member and strength to weight ratio 6
Fabrication Concerns 6
Fabrication 7
Assembly techniques and soldering considerations 7
Finishing and final weight of the truss in pounds 8
Results 8
Type of failure and rational for the test results 8
Ranking within your section 8
Ratio of Load failure (lb.) to truss weight (lb.) 8
Test results compared to predicted load failure and predicted...

...Roof Truss Essay
If I was building a 10 pitch roof I would use a roof truss rather than using a rafter. A roof truss is a rigid, strong frame work made up of wood members, such as 2” X 4”s, fastened and held together by metal connector plates. A roof truss consists of one or more triangular units constructed of straight pieces that are connected at the ends by joints. Personally roof trusses are superior due to its number of different designs, they are very strong, and lastly they are installed quickly.
Wood trusses come in variety of different designs. They are used to make almost any building in the world because of its vast designs. When using trusses I would be satisfied with my house because I get to have the roof of my choice. Trusses also give an advantage to uniqueness in a house because they all won’t look the same. That is why I would prefer a truss rather than a rafter.
Trusses are designed to be very strong. They have a high level of strength and capacity. Using a truss roof will allow me to safely place weight on the roof. Having a strong roof is a benefit of a good roof that will last a couple of years. Trusses are so strong they can bare a fire since it takes a long time to burn out and since all the pieces are spaced out it will take a longer time to fall apart giving the people who live in the house time to evacuate....

...TASK
TRUSS BRIDGE
[pic]
BY RICHY R. THURUTHIYIL
CONTENTS
Common types of Trusses
1- Warren Truss
[pic]
A warren truss consists of alternatively inverted equilateral triangles which are rigid. It is made up of horizontal members and equal angled cross-members that are of equal lengths. It was created by James Warren and Willoughby Theobald Monzani in 1848. This design requires fewer amounts of materials compared to other types of trusses, therefore lightweight, easy to build, great view and is economical. The members are stressed by compression and tension during the application of a live load. It is easy to repair and maintain. An example of a Warren Truss bridge is the-----------
2- Warren Deck Truss
[pic]
This type of truss is similar to the Warren truss but the difference is that the structure is below the roadway. So it requires a few amounts of materials, is light weight, easy to build, usually build offsite therefore quick to build, better more open view o n top and is also economical. The top part of the truss is in compression were as the bottom part is in tension. The interior members...

...Truss Bridge
Physics 141
Robin Hoffmeister
There is many reason that we need bridges in every day of our life, from sufficient means to pass over a roadway, waterway, railway, or other structure. You don’t even think about them because it takes no effort to get over them and they are just there for your use. So if you don’t think of them for everyday use I highly doubt that you would think of the physics that is involved in putting one together or the kind of force the bridge can actually take. I am going to show you the max force a truss bridge can take by demonstration it to you in class and also by trying to calculate it. I am also going to go over the many ways that truss bridges can fail and come to a tumbling crash.
Before I get into the physics of the bridge you need to know what a truss bridge is and how it works. A truss is a structure composed of members connected together to form a rigid framework. Members are the load-carrying components of a structure. In most trusses, members are arranged in interconnected triangles, as shown below. Because of this configuration, truss members carry load primarily in tension and compression. Because trusses are very strong for their weight, they are often used to span long distances. They have been used extensively in bridges since the early 19th century; however, truss bridges have become somewhat less common in...

...deflection and strain, associated with a simple truss subjected to a loading at its bottom end as would be the case if a constructed bridge was subjected to loadings by cars, trucks, trailers, pedestrians, etc. The set up contained an instrumented truss mounted in a test frame with strain gauges attached to the center of each truss member and a linear potentiometer displacement transducer (LPDT) placed underneath the truss assembly to measure displacement. Experimental data collected as loading on the bottom of the truss increased was compared to calculated results obtained by applying the theoretical formulas.
II. Objectives:
The main aim of the Simple Truss lab was to observe the behaviour of a simple truss that was subjected to a symmetrical loading, by measuring the deflections and strains in the truss and comparing analytical and experimental results of these deflections and strains.
III. Instrumentation and Test Procedure:
Fig 1.1 Truss Test Set-up
The test specimen consisted of two truss networks as can be seen in Fig 1.1 above. The six outer members are hollow whilst the inner eight members have a solid cross section. The hollow members are 9.48 mm outer diameter and a 0.87 mm thickness, whilst the solid members have a cross sectional diameter of 6.35 mm; all members are of length 335 mm. These length...

...Task 1 Young’s Modulus E = 170 x 103 MPa Poisson’s ration v = 0.3 Yield Stress = 290 MPa Ultimate Stress = 480 MPa Passport Number: A00740458 Table 1.1: Load Acting on Joint Joint 3 4 5 Load in Newton 9.81 x 8 9.81 x 5 9.81 x 4 Load Equivalent(N) 78.48 49.05 39.24
Figure1.1: Finite element Truss Model 1
Figure 1.2: Meshed FE Model
Figure1.3: Meshed FE Model with Load Constraints
2
DISCUSSION Element Type Chosen for Meshing (Link 2D Spar 1): The element used for the analysis of the FE model is the 2D spar 1 of the Link 1 element type. 2D Spar 1 can be used extensively in 2Dimensional and one dimensional truss analysis, link analysis, etc. The Link 2D Spar 1 element is uniaxial, that is, deformation is analysed along one axis. The element was used in the analysis of this truss because of its elements’ uniaxial tension-compression feature and nodes degree of freedom, each node undergoing a translation along x-y direction. One of the uniqueness of this element type is the disregarding of any bending of the element, just like that of a pin-jointed structure.
Figure 1.4: Element Type dialog box Real Constant: The real constant defines the cross sectional area of the model.
Figure 1.5: Real Constant Dialog box 3
Material Model: The material Model used in this analysis is the Structural Linear Elastic Isotropic material model. This analysis is categorised as static structural analysis. It analyses the effect of a steady loading...

...Semester Project Part 1 – Structural Failure
Cm 220 – Introduction to Structural Design
Due Date 10/03/05
On January 18, 1978, just four years after completion, the space frame roof of the Hartford Civic Center came crashing down 83 feet to the floor after a snowstorm. The majority of the blame for this disaster was placed squarely on the shoulders of the design engineers and architects who overlooked vital miscalculations and failed to fixdesign flaws when they started to appear. (Kaminetzky 220)
In 1970, Vincent Kling agreed to be the architect for the project. He hired Fraoli, Blum, and Yesselman, Engineers for the structural design. Construction on the Hartford Civic Center project started in 1972 with the plan to build an arena with a 2.4 acre, state- of-the-art, space frame roof. The proposed roof consisted of offset upper and lower grids made from horizontal steel members that were connected every thirty feet by steel diagonal members. The upper horizontal members were braced by additional steel diagonals, and the main diagonals were braced at their mid-points by horizontal steel bars (Dorris 284). The roof frame was completely assembled on the ground and inspected before it was lifted into its final position. Upon inspection, excessive deflections in some of the nodes were found. The engineers were notified, but nothing was done to fix the problem. The roof was lifted into position and deflection...