1. School Of Architecture, Building &
Science
Building Construction 2 (ARC 2513)
Project 1: Understanding Forces in Skeletal Structure
Prepared by:
D a n i e l Ya p C h u n g K i a t 0 3 0 9 1 0 0
L o o G i a p S h e n g 0 3 1 0 3 9 0
C h r i s t i o d y 0 3 0 4 1 9 1
Te o K e a n H u i 0 3 1 0 1 6 5
G a n C h i n B o n g 0 3 1 3 7 3 2
2. Content Page Page
Introduction 1
Design Process 2-3
Design Solution 4-5
Force Analysis 6-7
Model Constructed and Detail 8
Model Testing & Failure 9
Efficiency 9
Design Improvement 10-11
Conclusion 12
3. Introduction
Architecture, not only consisting design concept, form and
spatial quality but also the structure as it helps in constructing the
architecture. As a successful architecture, structural strength of the
architecture should be concerned during the design process. There are
various types of supporting structure but skeletal structure construction
are nowadays widely used in most of the architecture in the world as
building support. Therefore, it is important for us as an architectural
student to study how these skeletal structure works and influences the
stability of an architecture.
In this project, we are required to understand the skeletal
structure and the components and how they work. In order to show our
understanding, we were required to create a convincing structural model
to show our understanding of how a structure works under a load.
4. Design process
Design 1
Triangular core to distributes load could be a very strong structure. The triangular core was pre-
stressed to oppose the load force (mechanism of spring). The triangular core was joined with a
square base to maximize the base area of the structure. The tip of the triangular core are faced
up and down respectively at each level to distribute the load force evenly. The weakness of the
structure is the absence of vertical structure.
Design 2
The theory of pre-stress was still applied in this model. The square base provides larger base
area and better stability. The square base also provides maximum number of pre-stressed
column. Zigzag bracing were used to support beams meanwhile cross bracing used to maintain
the form and prevent the structure to be twisted. This design has its potential and with proper
bracing, it can be a very strong structure.
5. Design 3
Squared base with 8 columns at each level produce a very strong structure.
The columns are bended inwards a little to make sure it breaks inward.
Therefore, there are square bracing inside to prevent the bended column from
breaking. A-bracing is use for vertical bracing to support the beams and to
prevent the square bracing inside from breaking. Each popsicles stick are
supporting each other. This design distributes the load force to different
direction so force becomes weaker and weaker.
6. Design solution
Learn how is a building’s fundamental work. Besides, we also learn about pre-stretch method. Explore
how to tie to thing two string together to get maximum outcome. Learn how much loads that one popsicle
stick can handle.
Double square diagonal base
The square diagonal base give good impact and give maximum strength to the base as supporter. The
double layer of popsicle on the base support and giving stability to the vertical structure where are going
to place it on the base. The mechanism is the double layer of the popsicle stick will clip the vertical
structure so it giving more balance and stability.
The 4 pre-stretch column
The 4 pre-stretch column is giving a lot of benefit in a way to handle the load. The 4 column also became
the connector between the ground level to the next level.The mechanism is using 8 popsicle stick as the
vertical structures which tied together as two per column with leaving gap in between the structure to give
a space for the popsicle stick to stretch and support each other when the load force down from the top.
7. The balance slot in triangle bracing
The triangle bracing is the usual bracing that the being used by construction as structure supporter
nowadays. The slot in triangle bracing being bring into the skeletal structure. The slot in triangle bracing
giving a lot of benefit and advantages. The center part is to help the triangle bracing keep stable. The
mechanism is slot in the bracing that create a triangle shape that make the popsicle stick force each other
and force it to the 4 pre-stretch column. the bracing we put it on 4 sided of the structures and it helps a lot
on handle the load that force down to the structure.
Consistency of tying the string
Consistency is the most important thing on tying thing. For example this skeletal structure use string as
connector if the consistency and the way of tying the string is not right so the structure and connection
will decrease the strength and the stability of the structure. So for this skeletal structure the string tying
has been set like the number of tying. The mechanism of tying system is the string come from all the
sided and way with the same number of repetition with same loose-ness that given to every repetition.
8. Force Analysis
The characteristics of a Popsicle stick is experiment and tested. We
realized that it actually can be bent, so it has a tensile property and we have decided to
make use of it. In order to create a strong tower, we need to make use of all the
possibilities of Popsicle stick. The idea is to create a model with tensile strength and
using it to withstand the heavy load force and transfer it to other direction rather than
just acting downwards.
Pre-bent – To lead the force to the direction where it bends when force is exerted.
This is to predict the direction where the Popsicle stick breaks and from there, reinforce
it. A straight vertical column is unpredictable where the direction it breaks. Therefore it
is difficult to control the direction of force. A horizontal beam is placed at both ends to
hold them firmly and preventing them from shaking.( Shown in diagram beside)
Load
Force
9. Another shorter pre-bent Popsicle stick is placed in between two pre-bent
columns to carry the force transferred from the columns. By doing so, the originally
weakest point of the column now separate the entire column into two, making it harder
to bend. Just by adding a beam in the middle between two pre-bent columns
significantly enhances the strength.
The way it works is that the load force coming from top will compress the pre-
bend columns. After a pre-bend beam is added in between the middle of two pre-bend
columns, the heavy force transferred is reduced due to the tensile property countering
the force. The reason of using a pre-bend beam is to make is easily bendable in its
already bent position. This way it reduces the overall load force, like a spring.
To further enhance it, an inverted ‘V’ shape bracing is used in all sides of the
structure. Not only it shares the load by making use of the horizontal beam to transfer
the load, it also prevents the whole structure to tilt to 1 side. Besides, it holds the shorter
pre-bent beam from bending too much and break.
The idea is to be able to reduce the load force and to direct the force
experienced to all directions instead of just acting downwards.
Load
Load
ForceForce
10. Model Constructed and Detailed
After finish testing mock up model which only giving
unsatisfied result which became challenging thing to find out the problem
and solve it with the 4 method. After found out the problem, the 4 method
that became our specialty and best method to construct the skeletal structure.
84 popsicle stick is the number to construct the skeletal structure. after
counting the popsicle stick start to weighing the structure which the weight
reach exactly 100 grams and the height of the tower also reach the
requirement height or the minimum height that has been stated which is 30
cm.
First Experimental Model
11. Model Testing & Failure
The first testing is going smoothly. The structure handle 104 kilogram
without cracking any of the popsicle stick or structure. Stop at 104 kilogram
because out of loads at that time. After that, the lecturer require a test for
submission. Unlucky the lecture only bring 40 kilogram load to the studio.
After testing on studio the structure still can handle without cracking
anything. So all of the group member doing the final test at gym which
supply more loads. Then for the final test, the structure end up with satisfied
result which can handle load more than 100 kilogram which exactly 108.75
kilogram. About the structure it’s not breaking the popsicle stick it’s only fall
down because of the structure tilting at the moment and make the bracing all
pop out from the place where it should be.
Efficiency
Efficiency =
Height X Load_______________
Mass
=
_______________30.0 X 108.75
100
= 32.625
12. Design improvement
Our initial design was to use pre-stressed column to execute opposite force from the load. We
used 8 columns for every level and stressed the sticks (to create the mechanism of spring). Then
we have zigzag bracing as our vertical bracing and cross bracing for horizontal bracing. The
methods of both bracing are slotted-in. It gives us unsatisfied result. We used 66 sticks and it
breaks at 30KG.
We replay the mock up video to observe and analysis how and why the model were crushed. We
then knew that our structure was not crushed directly vertical because the upper structure actually
slide off aside causing the middle structure to gets imbalanced and it crushed downwards. We
checked on the crushed structure and noticed that there weren't any broken stick. The major
problems are not the structure is weak itself, it was the positioning and equilibrium that twisted
the structure. The structure did not maximize its load endurance. The factor behind the structure
failure were the inappropriate bracing applied and inconsistency of workmanship caused the
structure to be tilted aside.
13. We got aware of the importance of workmanship therefore, we made up several systems
and methods in model making to ensure every one using the same way. We then
realised that the pre-stressed column are not as strong as pure vertical column so we
changed our plan. We decided to stressed the stick a little inwards to force the stick to
break inwards rather than using it as pre-stressed. This method ensured that if the
column breaks, it would definitely break inwards.
We then strengthen the inner side by adding bracing into the weakest point of the
bended column which is the middle of the stick. Moreover, we improved our zigzag
bracing to A-bracing. The A-bracing functioned as two; supporting the bracing of the
bended column and to maintain the beam in its position. This method distributes the
force from the load to many and different directions, minimizing the force each time it
changes direction. We have improved from the theory of opposing its force to
distributing load force to different directions.
14. Conclusion
In the conclusion, a lots of experiences and
understandings have been gain through this structural model making.
Throughout this project, we have learnt how a skeletal structure works under
loading. In order to maximize the load handled by a structure, several
experiments have been carried out. We have tried different ways of bracing,
different way of tithing method and also different types of structure.
After been through these experiments, we have learnt that
bracings are needed to strengthen the structure as they play an important role
in maintain the original shape of the structure.
Besides that, our creativity have also been aroused to create
different kinds of structure and test them to their limit. This project have
indirectly help us to realize that how an organic structure can possibly
construct in different skeletal structure.
