1. Abstract There is a high amount of necessity in third world countries for many concepts in mechanical engineering to inspire learning and choosing engineering as their career path. One of these concepts is the knowledge of identifying the deformation and strength of typical known mechanical materials. A universal mechanical testing machine is widely used to observe the mechanical properties, such as the modulus of elasticity and ultimate tensile strength, of various materials such as steel and aluminum. These properties can be measured by applying tensile or compression stress on the specimen. The determination of such properties is important in manufacturing processes. Client’s statement “design a mechanical testing machine to demonstrate the concepts of stress, deformation and strength of structural members.” Purpose:- Our purpose is to design a mechanical testing machine to demonstrate the concepts of stress, deformation and strength of structural members. ObjectivesFunctionsMeans operational Stable while staticLow center of massStrong static structureStrong material Stable while testing Grips/handles placed in the middle of the machine Shock absorbersSupporting arms Testing techniquesScrewsSpring Weight blocks ScrewsSpring StiffStainless steelTrussesAdditional screws PreciseStrain gauge sensorLoad sensorWeighed blocks Safe Protects user from injuries due to device Smooth edgesRubber edges Child lock, safety sensor Protects user from injuries while transporting Smooth edgesControlled braking system Provides safety equipment First Aid kit Safety operating instructions board Emergency automatic power-off switch Protects the environment Non-toxic materialRecyclable material Waste-disposal compartments Simple Using the device easily Computer graphing system Electronic devices and monitors Wide grips to hold the specimen in place easily Portable Transporting the device easily Wheels Low weight materials Packaging bag Hinges & screws Rubber handles Attaching/detaching Rotatable large screws Secure locks Parts of the machine can be fixed to each other Economical Minimizes construction cost High quality/Low cost material (local) Easy assembling to minimize labor CAE analysis to locate un-needed parts Minimizes maintenance cost Durable materialSimple design Organized maintenance schedule Provides simple manufacturing process WeldingSimple machiningStandard parts usage The table below shows the main objectives that the design should have according to the client’s statement. Moreover, it shows the objective’s functions along with their several means. One of our engineering design process is to come up with three conceptual designs. This was done by choosing different means for each objective and come up with a design for each. Design I (Double tester) Design II (Single tester) Design III (Technical tester) Design specifications: 1)Design’s outer body is made of stainless steel 2)The dimensions are 100 cm in length, 70 cm diameter and 45 mm thick 3)The specimen that is going to be tested is a cylindrical Lead 4)The dimensions of the specimen are 15 mm outer diameter, 10 mm inner diameter and 45 mm thick and the upper and lower lengths are 50 mm Design details: The image on the left is the modified version of the conceptual design. The design consists of an upper and lower body that are fixed together. There are two weight holders, one is fixed at the top of the upper body and the second weight holder is fixed at the lower body. Both of these weight holders have the tendency to move down due to gravity. In order to stop that from happening, four poles are placed through them, two are fixed through the upper body and the other two at the lower body. There two grips located and fixed at the top and the bottom weight holders. These grips hold the specimen tightly. For tension: After placing the specimen, the bottom two poles at the bottom weight holder are taken out and weights are added. The greater the weights, the more the specimen gets the tendency to deform due to tension. For Compression: The top poles are taken out and weights are added at the top weight holder. The same phenomenon is applied here. The double tester design was divided into four subsystems. The subsystems are as follows: 1) Device structure 2) Load application 3)Deformation measurement 4) Transportation Cylindrical body: the outer body supports the whole device. Weight holders : holds the weights and the grips The four holding poles : holds the weight holders when applying tests. Digital Vernier Caliper technique : A Digital Vernier Caliper is attached next to the top and bottom grips. The caliper is calibrated to zero at its center where the measuring slider is placed. The measuring slider is attached to the grip using a string. Deforming the specimen will cause the grips to move up or down which will cause the measuring slider to slide and record the deformation length. Lock rubber wheels: in order to ease the movement of the device, rubber wheels were used. Locks are used to keep the device stationary. The design is in a shape of a cube with two weight holders. One at the top and one at the bottom,. The design consists of 4 poles. Two of them goes through the top weight holder and the other two goes through the bottom. The double tester was chosen as the final design. The mechanism is explained below. The single tester is designed to measure only the tension. It consists of a specimen holder, a motor, a rotating rod, and a Newton meter. The motor twists the rod and gives the specimen a tension force. Once the deformation occurs, the Newton meter measures how much force was used to deform the material. Therefore, by using the stress/strain formulas, we can find the tension. The technical tester is highly reliable since it is a hydraulics/computer based design. It automatically measures the diameter of the specimen. Moreover, the device can easily deform the specimen by using the hydraulics method. The only problem is that the design would cost a lot of money, so it is not affordable in third world countries. “THE PI INVENTERS” (STEPS II) Suhaib Al Bastaki920011870 Ahmed Faisal920012497 Ahmed Mostafa920012479 Khaled Abdulla920011538 Tannaf Hamad920012168 Abdulla Al Shehhi920010865 The graph above shows the stress/strain curve of the lead specimen. At (3), it is at the elastic region and from there it starts to deform. Furthermore, when a 12 MPa of pressure was applied it reached the breaking point. That pressure is resulted from an application of 942 N force. As shown in the cosmos image of the top weight holder, the amount of force used to deform the specimen will not result in a failure in the mechanism process.