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Lab report bending moment in a simply supported beam

The set up of the experiment consist of a special beam with a cut section and is placed on the simple supports provided.

The span of the beam is set by us 2 where we fixed it at 900mm. Later on, both of the distance of the cut section from the right support, L4 and distance of the load cell form the centre of the beam cross section which is 300mm and 175mm respectively.

  • For example, if a worker gets injured during construction, that work is entitled to paid leave, plus the hospital cost will be paid by the company or insurance, and as soon as the worker is back to full health, he can come back to work again;
  • The theoretical value and the experimental value differ due the errors that are committed by human or the environmental changes;
  • When the beam is placed on its flat side its inertia is less than when positioned on its thin side where the inertia is bigger;
  • For stability of the reading the indicator must be switch on 10minutes before taking readings 3;
  • Remove the loads starting from 2;
  • When a load is applied to the beam, the beam would physically bend downwards.

The indicator is switched on 10 minutes beforehand so that it would stabilize. This experiment begins by placing different loads at different distance for each different case.

The reading on the load cell indictor is recorded for each different case. Through the reading obtained the experimental values of the bending moment can be obtained. While the theoretical value is obtained through the formula shown in the theory part.

Bending of Beam Lab Report Essay

With both values we can compared the difference in it. These differences are due to errors that are caused from environmental, human or systematic errors. With the overall percentage error is determined, it shows us the difference in the actual and theoretical value. This is especially important when it comes to the design of a reinforce beam which is able to support external loads acting on it and being practically usable for buildings design.

A pair of simple supports. Special beam with a cut section. A set of weights with several load hangers. Connect the load cell to the digital indication. Switch on the indicator. For stability of the reading the indicator must be switch on 10minutes before taking readings 3.

Fix the two simple support to the aluminum base at a distance equal to the span of the beam to be tested. Screw the supports tightly to the base. Hang the load hanger to the beam.

Placed the beam on the supports. Placed the load hanger at the desired location. Note the indicator reading. If it is not zero the tare button on the indicator. Place a load on each load hanger. Record the indicator reading. This represents the force at the cut section. Remove all loads from the load hangers and apply a different set of loading and at different set of loading and at different locations.

Repeat step 6 to 11 another 5 sets of readings. When a load is applied to the beam, the beam would physically bend downwards. This situation occurs lab report bending moment in a simply supported beam to the external loading that was applied to the beam.

This causes the distribution of load throughout the beam, thus the beam bends with the contact of loading. For this experiment, it is separated in to different cases, where we put different weight of loads at different distance from the cut section. Three types of forces are produced when the external loading is applied to the beam that is the shear force, normal force and bending moment. The shear force acts on the shear section of the beam causing both sides to slide each another in the plane of the area.

Followed by normal force that acts perpendicularly to the beam is due to the perpendicular area which tend to further or closing the gap of the two sections. The third force acting on the beam is the bending moment that has a high tendency that causes the rotation of the beam body about a certain axis within the area of the plane. With all these forces that are present in the reactions of the beams, equilibrium is achieved.

When external force is applied that causes the beam to break lab report bending moment in a simply supported beam is countered by the internal force that acts throughout the beam span to prevent the beam from failing. But if the load allowed is exceeded eventually the beam will crack thus failing the structure. Will the readings of the load cell differ from above if it is placed at 100mm from the centre of the cross-section? If your answer is yes by how much.

If your answer is no, then why. The theoretical value and the experimental value differ due the errors that are committed by human or the environmental changes. Therefore causing low accuracies in the percentage error that is obtained.

  • Most of us should take notice that the indicator should be allowed to stabilize itself by leaving it switched on for 10 minutes before conducting the experiment;
  • Fix the knife edged supports on the beam and screw them tightly to the base;
  • Remove all loads from the load hangers and apply a different set of loading and at different set of loading and at different locations;
  • Make sure the reading is zero;
  • Record the readings on a record sheet;
  • Software will automatically gather all the data of experiment and save it in memory.

These errors can be minimized or higher accuracy can be obtained by taking several precautions throughout the experiment.

The average percentage error for this experiment is 3. State the probable factors that affect the accuracy of the experiment. As previously stated, errors occurs in this experiment. One of the probable factors is the sensitivity of the load cell indicator.

Most of the time students tend to begin the experiment straight away after switching on the indicator. Most of us should take notice that the indicator should be allowed to stabilize itself by leaving it switched on for 10 minutes before conducting the experiment.

Also when conducting the experiment makes sure there are no vibrations that cause the settings of the beam structure to move. This slightest movement causes changes in the reading and causes inaccuracies. Other than that human error also affects the reading of the indicator. People who are passing by the beam structure causes wind movement and thus vibration in the air.

By making sure that there are no vibrations and movements we are able to minimize the inaccuracies in the reading obtained. The next error occurs with our own carelessness.

By miscalculating the distance of the load from the shear section makes the theoretical value and experimental value totally going off the charts. We might also encounter extreme values in some of our readings. To remove any of these errors, the whole experiment is repeated a few times so that we can exclude the extreme values. Also by taking the average readings, the error is lessened and we are able to obtain a higher accuracy result.

These particular forces are shear force, normal force and bending force. Through our calculations, we are able to see the differences in the theoretical and experimental of the bending moment values. The overall error percentage obtained is 3. In conclusion, the bending moment at a cut section of a beam is equal to the algebraic sum of the moment acting to the left or right of the section.

With this knowledge we are able to design a structure with the usage of reinforce beam with the capability to withstand external forces without losing its balance.