ABSTRAK

Strecther is the equipment used by a hospital to carry the sick or injured person. When using the stretcher, an employee easy to carry the patients out and in from ambulance. Strecther also must used the lightweight material to carry the patient easily. Basically, the strecther must be carried by two or more people. Next, the objective that we get from our project is to define body mechanics like process of using thebodysafely and efficiently. Someone will manipulate the trunk by standing at the waist and helping with weight shift and proper upperbody mechanics.Body mechanics means using thebodyproperly to coordinate balance and movement. After that, the stretcher must be test the strength and durability of strecher.

Besides that, to make a stretcher with a low price with use pvc, mild steel, bold and nut, and canvas. To know the step to make a stretcher refer from hibbeler book such as the calculation to know the heavy load and give many ideas to design the stretcher. The important is the size of stretcher because must be easy to enter in ambulance. After that, how to make a stretcher need to installation also important in our final project.

The result can be seen in the tests, from the mass can know the test is pass or fail. From the tests can solve the problem to make a stretcher such as want to use the plywood to put on top of the stretcher as planned but we change our design with material by using canvas on top of our stretcher. The conclusion of our final project can learn more knowledge from static subjects. In static calculations needed to create something that can the structure to be strength and durability.

INTRODUCTION

Stretcher is akindoflitter,oftenofcanvasstretchedonaframe,forcarryingthe sick,wounded,ordead. A similarlitteronwheels,adaptedforuseinambulancesand hospitals. Anapparatusused for moving patients who require medical care. A basic type (cot or litter) must be carried by two or more people. Whereas a wheeled stretcher (known as a gurney, trolley, bed or cart) is often equipped with variable height frames containing wheels, tracks, or skids. In American English, a wheeled stretcher is referred to as agurney. The name comes from a horse-drawn cab patented in the USA by J. Theodore Gurney in 1883 which bore a similarity to early wheeled stretchers.Stretchers are primarily used inacuteout-of-hospital care situations byEMS, military, andSearch and rescuepersonnel. However they are also used to hold prisoners duringlethal injectionsin the United States.

OBJECTIVE

1) Define body mechanics2) To test the strength stretcher3) To test the durability stretcher

LITERATURE REVIEW

Principle of Moment

One of the areas where solid mechanics as discussed in this book is most effective is in the case beam loading. The loads on a beam can be point loads, distributed loads, or varying loads. There can also be point moments on the beam. The beam itself is supported at one or more points. The conditions at the support depend on the kind of support used. If the support is a roller, it can only have a reaction perpendicular to the motion of the roller. If the support is a pin, it cannot carry a moment. If the support is fixed, then it can have a reaction in any direction and support a moment as well.

In the above image, a simple beam is loaded at the center by a loadP. It has a pinned contact at one end, and a rolling contact at the other end.

The above image shows an ideal moment acting at the center of a beam. Anideal momentis one which is not associated with a force.

The general method is analyzing beam problems is to find the loads, reactions, and moments, and come up with the values for the loads and moments at each section. This, in general will be a piecewise function of the distance along the beam.

For loads, we set up axes and this decides the sign of the force. For moments, we set the convention that the clockwise moment is positive.

Example

1.Consider the case of the beam discussed earlier shown above.

The beam has reactionsR1andR2acting on each of the supports.

R1+ R2= P

Applying symmetry, we have,

R1= R2

So that,

R1= R2= P/2

The above image shows the shear diagram for this problem. Note that the positive and negative directions are conventions, but it is important to choose one direction for positive shear and stick to it. As can be seen, the shear value changes at the point of application of the load.

The above image shows the moment diagram for the beam. The moment varies linearly from the supports to the middle.(The value at the middle should be PL/4).Note that the moment is maximum at the middle and zero at the ends, so that the effect of the moment is maximum at the center. In later chapters we will see that the stresses and strains due to moments are the most important ones for beams.

ExampleBAA

Moment at point A, (assuming anticlockwise is positive)+ Ma= Rb(40) - (100)(30) = 0 0=40 Rb 3000 Rb= (3000) / (40) Rb= 75 kN

Total Fy, (assuming force upwards is positive) + Fy= Ra + Rb 100 = 0 0= Ra + 75 100 0= Ra 25 Ra = 25 kN

METHODOLOGY

Firstly in our project is to make stretcher that can reduce cost and withstand the load exerted on . These are some methodology we use in our project:-Literature survey is one our methodology, we use book to refer the appropriate material and step to build a stretcher. From the book we can develop more idea to design a stretches that fill the criteria that we need, that is cheap and strong. Book that we refer is Hibbeler .

Figure1. concept strecherPicture above show the first concept of our stretcher that are we will use as reference for our stretcher. Our project outcome might not be the same as the concept or the research design that shown above.

DataThere are a few data need to build our own stretcher for the static final project. data can be found by doing some research about the stretcher and when to the nearest medical Centre to take its measurement. The data that could be found is like the picture below.

Top view Rear view

Procedure 1. Firslty we gather all the metal that we cut into several part and dimension

2. To join the main part , we used and nut and bolt method . Joint between them is easy because the material already have thread . The joint also is reversible .

3. For the wheel , we used welding method . This is permanent so that joint is strong and stable .

4. Lastly for the upper part we used wood that is strong that can withstand people weight ang supported by some metal .

Below is frame of our stretcher

Cost1. Bolt RM12.802. 3 HIL IND Rubeer Caster SwivelRM26.003. 3 IND Rubeer Caster RigidRM20.004. 11/2x1/2 Blotted AngleRM120.00 Total : RM178.80

RESULTS AND DISCUSSION

Outcome of Project

3D view of Project

View from side

Calculation:

FBD,70 kgRaRb0.6 m0.9 m

Zero force member

W = mg= (70))(9.81)= 686.7 N

Moment at point A, (assuming anticlockwise is positive)+ Ma= Rb(1.5) - (686.7)(0.6) = 0 0=1.5 Rb 412.02 Rb= (412.02) / (1.5) Rb= 274.68 N

Total Fy, (assuming force upwards is positive) + Fy= Ra + Rb 686.7 = 0 0= Ra + 274.68 686.7 0= Ra 412.02 Ra = 412.02 N

CONCLUSION

From the static project that we have done we can conclude that all the static knowledge that we learn in class can be applied in stretcher design and our daily live . Example is when want to calculate moment and force that exerted on the stretcher .We most know the possibility for the stretcher to fail and exceed the limit of its stress .

Futhermore we used the cheap material in order to reduce the cost of our stretcher ,that is the second objective of the profect . Then we used the simple method to join the main material . We used the bolt and nut . For the wheel we used welding to join it .

So we must understand that stretcher is very important to support the body of the patient and can move smoothly . Or not it will harm the patient and the people around them . Safety is the most important after all .

REFERENCE

1. Gere, J.M and Goodno, B.J., 2009. mechanics of material . 7th Edition, Cengage Learning.

2. Beer, F.P, Johnston, E. R. and Deworlf, J.T., 2009. mechanics of materials, 5th Edition, Mc Graw Hill.

3. Hibbler, R.C., 2008. Mechannics of Materials, 7th Edition, Pearson Prentice Hall.

4. http://en.wikipedia.org/wiki/Stretcher

5. http://www.passmyexams.co.uk/GCSE/physics/turning-effect-forces.html