lab report structure continuous beam
- 1. 1 THEORY A continuous beam is a statically indeterminate multispan beam on hinged support. The end spans may be cantilever, may be freely supported or fixed supported. At least one of the supports of a continuous beam must be able to develop a reaction along the beam axis. An example of a continuous beam is presented in Fig. 1a. The supports are numbered from left to right 1, 2, 3 and 4. The moment of inertia remains constant within the limits of each span, but varies from one span to another. OBJECTIVE 1. To determine the reaction for each clamping support when particular point loads are applied on the beam at the support. 2. To compare the reaction by the reaction by experimentally and theoretically.
- 3. 3 PROCEDURE 1. The beam 3 unit into the structure frame as shown in figure was setup,measurement was used to meadured the support beam distance. 2. The test beam of 800mm long was placed, 25mm steel plate on the support beam as in figure. The beam is in level, the spirit level gauge place on top the beam. 3. The long hanger adaptor was placed in the test beam. Two piece required and place the load hanger onto it. 4. The reading of reaction measured by the each load cell were taken when load is applied. RESULTS Reaction of a Continuous Beam. Rest result Load(N)(left)(1-2)= 1oN Load(N)(right)(2-3)= 1oN Initial Final Net R1(N) 29.4 32.8 3.4 R2(N) 30.3 43.3 13.1 R3(N) 31.3 34.8 3.5 Theoretical beam support reaction Load (N) R1 (N) R2 (N) R3 (N) 10 3.125 3.125 3.125 Percentage of error Load (N) R1 (%) R2 (%) R3 (%) 10 8 4 12 Reactions of a continuous beam with uniformly distributed load (UDL). 750MM
- 4. 4 PROCEDURE 1. The beam support 3 units were setup into the structure frame as shown in figure, measurement tape was used to measure the support beam distance. Aligned the pier and fastened the lock nut at the bottom of the pier. 2. The test beam of 800mm long was placed, 25mm steel plate on the support beam as in figure. The beam is in level, the spirit level gauge place on top the beam. 3. The pier load cell cable was connected to instrument panel. 4. Initial reading for ma, mb, fa, fb were taken. 5. Distributed load bar was placed at the top of the supports. 6. Final reading for ma, mb, fa, fb were taken. DATA Distributed load = 17.1 N/m Load (N/m) R1(N) R2(N) R3(N) Initial Final Net Initial Final Net Initial Final Net 17.1 29.1 31.6 2.5 29.4 37.8 8.4 31.0 33.4 2.4 Theoretical beam support reaction Load (N/m) R1(N) R2(N) R3(N) 17.1 2.40 8.02 2.40 Percentage of error Load (N/m) R1(%) R2(%) R3(%) 17.1 0 0 4 750MM Distributed load bar
- 5. 5 CALCULATION Theoretical beam support R1= 5𝑃 16 = 5(10) 16 = 3.125N R2= 11(10) 8 = 13.75N R3= 5(10) 16 = 3.125N Percentage of error R1 = 3.4−3.125 3.125 x 100 = 8% R2 = 13.1−13.75 13.75 x 100 = 4% R1 = 3.5−3.125 3.125 x 100 = 12% Theoretical for continuous beam with uniformly distributed load. R1= 3𝑤𝑙 8 = 3(17.1)(0.375) 8 = 2.40N R2= 10(17.1)(0.375) 8 = 8.02N
- 6. 6 R3= 3𝑤𝑙 8 = 3(17.1)(0.375) 8 = 2.40N Percentage of error R1 = 2.5−2.40 2.40 x 100 = 4% R2 = 8.4−8.02 8.02 x 100 = 4% R1 = 2.40−2.40 2.40 x 100 =0% DISCUSSION AND CONCLUSION For reaction for continuous beam to point load. Base on, experimental result value we got were R1=3.4N, R2= 13.1N and R3= 3.5, but value we got from theoretical were R1=3.125N, R2= 13.75N and R3= 3.125. the different at support R1 is 0.275N or 8%, the different at support R2 is 0.65N or 4% and the different at support R3 is 0.375N or 12%. For reaction for continuous beam with uniformly distributed load (UDL), Base on, experimental result value we got were R1=2.5N, R2= 8.4N and R3= 2.4, but value we got from theoretical were R1=2.40N, R2= 8.02N and R3= 2.40. the different at support R1 is 0.10N or 4%, the different at support R2 is 0.10N or 4% and the different at support R3 is 0.0N or 0%. The value that we got are not same base on theoretical calculation because, the apparatus at laboratory are too old. The value of loading are not accurate. Other than that, wind from the fans in laboratory can effect to reading on display. REFERENCES 1. Donald P.Codute (2012). Structure Engineering (2nd ed). Us 2. Braja M.Das (2011). Principles of structure engineering (9nd ed). British 3. Robert D.Holtz (2010). A Introduction to structure Engineering (2nd ed). British. 4. Robert W.Day (2009). structure engineers handbook (2nd ed). Us