MEMB123 MECHANICS STATICS SLIDES PRESENTATION By: ALIF HANIFA BIN CHE HASSAN (GL) ADIBAH BINTI HANUSI AHMAD ZUHAILI BIN ZAINAL BASRI ALBOGAMY, KHALED NAWAR M ARIF AZRAEI BIN SAHABUDIN CRISTINE HURING ANAK PATRICK KENNEDY DANIA QISYTEENA BINTI SALAHUDDIN HAFIZAH HANUN BINTI ABU BAKAR
CRITERIAIn this project, we designed, built, and tested a model bridge with the measurements as stated below: 69cm 49.2cm Actual measurements for our design
PROTOTYPE DESIGN AND TESTING DIMENSIONSWe’ve been told that the bridge should not be longer than 70cm. The widthof the bridge should be at least 5cm but not more than 10cm. The height ofthe bridge should not be exceeds 20cm above or 5 cm below “groundlevel”. The bridge also must span a distance of 50 cm. So, we had to think ofhow we’re going to use the sticks and getting some useful information aboutthem.•1 stick = 150mm•After calculating, we knew that we will need about 187 sticks for the basewhile total length of the bridge= 69cm
ANALYSIS/ SYNTHESIS/ CONCEPTUALIZATION We were making 2 tests to perform the bridge component strength.Test 1 - Tension TestObjectiveThe objective of the tension test is todetermine a recommended overlap distance fortwo tongue depressors in tension (taking intoaccount strength and total span length).Procedure1. The test specimens were built by gluing twotongue depressors together using differentlengths of overlap ( max. < 3/4"). We madesure to test at least 3 specimens for a givenoverlap distance to ensure more accurateresults. The hole was reinforced with extrapieces of tongue depressor.2. The sticks were placed in the vice on thetesting platform and the hole was reinforced atthe other end with tape.
Test 2 - Compression TestObjectiveThe objective for Test 2 is to determine amaximum length that designers should notexceed, to ensure adequate strength fromcompressions members.Procedure1. A ruler is used to prepare several specimensfor the compression test ranging in length from3” to about 10”. For members greater than 6”,two tongue depressors were glued togetherwith a 1” overlap length and then the ends wascutting to the desired length. At least 2 samplesfor each length are prepared to ensure somelevel of accuracy.2. To test the specimens, we were placed themupright on the scale and pushed down as shownin Figure 2 (using pliers may be easier on ourhands).
BRAINSTORMING IDEASTo make the start of the project easier, some questions were asked!!
MATERIALS•Tongue depressor sticks•A metal hook to carry theload at the center of thestructure•Glue gun and glue sticks•String/ masking tape
CONSTRUCTION METHOD1. Firstly, we decided on the design and laid it out on paper.2. Then, the sticks were measured and marked so they could be drilled for the pin joints.3. Next, we constructed the floor for the length of the bridge, or the struts we will apply the sides to.4. After that, we measured the length of the floor or struts. It is likely the bridge has to span a specified length.5. Finally, we attached each poles with ropes to the struts.6. Then, we constructed a number of identical poles by tied them with tiny rope we are going to join to the struts or floor.
TESTING PROCEDUREThe bridge has been tested to failure using the testing apparatus in thepicture since it must hold a minimum weight of 5 kg or 50 N. Efficiency ratio = test load/weight of model = 5 KG / 7.65 KG= 6.536
CONCLUSION At the end, we have accomplished the required task. We had a lot of fun, challenge, tire , and memorable experience that we have gained. The bridge task teaches us the values of determination, perseverance, creativity, logic thinking, time management, cost effectiveness, initiatives, and all this values can lead us towards success when we are working in group. Although we were facing a lot of difficulties in decision making and getting ideas but our cooperated team members were very patient and managed to solve the problems that we had during the construction. We started our project early so that we have time to modify and troubleshoot the problems. Flexibility, creativity and perseverance are our motto.