This document summarizes a report on investigating the relationship between measured and theoretical forces in a loaded redundant truss. The report includes an introduction describing truss determinacy, objectives to determine and compare experimental and theoretical forces, and procedures, results, and discussion sections. It finds differences between experimental and theoretical results due to measurement errors, but confirms the theoretical model. The conclusions state the objectives were achieved and precautions can minimize errors. Trusses are an important structural element and this experiment helps analyze truss behavior.

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The Report about :
Truss Engineering
University Of Zakho
College Of Engineering
Mechanical Engineering
Name: Rawa Abdullah Taha
Supervisor: Dr. Mahmood
April-2019

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List of Content :
 Introduction
 Objective
 Apparatus
 Procedure
 Result
 Discussion / Analysis
 Conclusion
 Refferences

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Introduction
Sometime a structure contains one or more redundant members depending on the
degree of indeterminacy (Figure1). These members must be removed from the truss,
otherwise one will have an insufficient number of equation to solve for the unknown
member forces. Slender members are not very useful in compression since they
buckle and lose their load carrying capability.
For example, in the following truss one of the two members AC or BD is redundant.
To solve the problem, once the truss is statically determinate and stable, the internal
forces can be calculated by using the method of virtual work as shown in Figure 2
Figure 1 Figure 2
.
To investigate the relationship between the measured forces in a loaded redundant
truss experimentally and theoretically

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Apparatus :

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Procedures:

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Result :
table 1 : Truss Dimensions

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Theory calculation :

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Discussion :
What is the relationship between the experimental and theoretical values
obtained?2. Will there be any changes to the angles of the frame with
loading?3. What are the precautions that should be taken in this
experiment to ensure its accuracy?1.
Through this experiment, we know that the theoretical results are
calculated to show theaccuracy of the experimental results.
As the results showed, there is different between theexperimental
and theoretical results due to some errors when conducting the
experiment. One ofthe main reasons is the digital force display haven’t
static when we conduct the reading. Besidesthat, it may also cause by the
equipment has not fully function correctly. It maybe cause by thedevice
which is not well maintenance. Furthermore, environmental factor in the
lab can also leadto some error during the experiment. This is because the
device is sensitive to vibration andmovement of wind.2.
When the loadings are applied during the experiment, there are changes
to the angles of theframe. The angle of the frames will change when
different loads are applied to it. However, thechanges are very small that
it cannot be seen from naked eyes.
It is because the loads applied aresmall and not able to make obvious
changes.3. There are some precautions that we need to do in order avoid
the mistakes and minimize theerrors during the experiment. Firstly,
the random errors like parallax error which will happen

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when measuring the distance. Thus, observer’s eyes should be
perpendicular to the measuringtape scale when measuring the dimensions
of the truss in order to avoid parallax error. Besidesthat, we need to make
sure that the indicator is switched on for 10 minutes and wait until
thereading is constant before taken the reading to allow the indicator to
reach its stability. A regularmaintenance is needed for the equipment so
that the equipment can function fully. Apart fromthat, we need to make
sure that there is no external force applied to the frame when
conductingthe experiment such as vibration in order to minimize the error.
Conclusion :
he objectives of this experiment have been achieved as we are able to
determine and investigatethe relationship between the measured forces in
a loaded redundant truss experimentally and theoretically.Besides that, we
also have investigated the relationship between the measured forces in a
loaded frame truss experimentally and theoretically.
In addition, we are able to check the linearity of the measured strain versus
the applied load. There is a different between the results of experimental
and the theoretical results which is caused by few errors.
Thus, some precautions can be taken to avoid and minimize the mistakes
and inaccuracy. Firstly, we have to make sure the apparatus that we used
is in good condition. Next, the parallax error can be reduced by taking the
average of the readings. The truss is an important element in current
structure trends. Trusses able to allow for the analysis of the structure uses
a few assumptions and the application of Newton’s law of motion
according static.
In the industry of construction, the used of application of truss applied for
some construction such as truss bridge and roof construction

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Refferences :
Book :
civil Engineering Laboratory Manual (2nd edition) Faculty of Civil
Engineering and Earth ResourcesUniversiti Malaysia Pahang
website:
http://www.scribd.com/doc/27381814/Truss-Full-Repor
http://www.scribd.com/doc/134932161/Force-in-a-Statically-
Indeterminate-Cantilever-Truss