FAKULTI TEKNOLOGI DAN KEJURUTERAAN MEKANIKAL
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
BMKT 2323 SOLID MECHANICS
LAB SHEET 3
SHEAR FORCE AND BENDING MOMENT
INSTRUCTOR’S NAME DR AHMAD FUAD BIN ABDUL RASID
STUDENT’S NAME MATRIX NO:
S1. MUHAMMAD HARDY BIN HAZRAMY B092210020
S2. AHMAD NUR SYAHMI BIN AHMAD YUSDI B092210497
S3. MUHAMMAD NUR HAFIZZUDDIN BIN SALIM B092210289
S4.
S5.
Learning Outcome LO2 Identify and display appropriate experimental techniques in
(LO):
mechanics of material through laboratory experiments.
Program Outcome: PO5 Ability to select and apply appropriate techniques, resources and
modern engineering tools, with an understanding of their limitations.
Synopsis: This lab activity will enrich students’ knowledge on shear force and bending
moment. Students are exposed to the concept of shear force and bending
moment at a cut section of a loaded beam.
Related Lecture’s 1. Equilibrium of a deformable body (Topic 1)
Topic:
2. Bending (Topic 6)
Prepared by: Dr Olawale Friday Ifayefunmi Date: 20 Apr 2020
Approved by Dr Muhammad Ilman Hakimi Chua Bin Date
LM/SLM/HOD Abdullah
Approved By: ………………………………………………..…..
Date: …………………………………………….........
1.0 THEORY
Beams are defined as structural members supporting loads at various points along the member.
Transverse loadings of beams are classified as concentrated loads or distributed loads. One of the
main concerns that should be put into consideration when designing beams for strength is how the
material and the cross section of a beam of a given selected span should be selected if the beam is
not to fail under a given loading.
Applied loads result in internal forces consisting of a shear force (from the shear stress distribution)
and a bending moment (from the normal stress distribution). For prismatic beam, that is straight
beam with a uniform cross section, their design depends primarily upon the determination of the
largest value of the bending moment and shear force created in the beam by a given loading. The
determination of these values and of the critical sections of the beam in which they occur is greatly
facilitated by drawing a shear force diagram and bending moment diagram. The variation of the
shear force, V (N) and the bending moment, M (Nm) along the beam may be investigated from these
diagrams. The values of V and M at various points may be obtained either by drawing free body
diagram of successive portions of the beam or from relationship that involves the applied load, shear
force and bending moment.
Determination of the maximum normal stress, σmax and maximum shearing stress, τmax
requires identification of maximum internal shear force and bending moment. Shear force and
bending moment at a point are determined by passing a section through the beam and applying an
equilibrium analysis on the beam portions on either side of the section as shown in Figure 1 and 2.
Sign conventions for shear forces V and V’ and bending couples M and M’.
Figure 3 Shear Force FBD
Figure 4 Bending Moment FBD
2.0 EQUIPMENTS/ EXPERIMENT APPARATUS/ CONSUMABLE MATERIALS
Fig 5: Shear Force Apparatus
Fig 6: Bending Moment Apparatus
3.0 PROCEDURES/ METHODOLOGY
Part A (Shear force)
1. Hang the load hanger to the beam at 40mm away from the cut position.
2. Record the force gauge reading. This represents the shear force at the cut section.
3. Repeat the test with incremental load 100g until 500g.
4. Record all data in a table.
Part B (Bending Moment)
1. Hang the load hanger to the beam at cut position.
2. Record the force gauge reading. This represents the bending moment at the point of loading.
3. Repeat the test with incremental load 100g until 500g.
4. Record all data in a table.
4.0 RESULTS
Part A (Shear force)
Table 1 Shear forces with variation of load.
Shear Shear
Error
Load Load Force Force (The-
Percentage
(g) (N) (Exp.) ory)
(%)
(N) (N)
0 0.1
100 0.6
200 1.2
300 1.8
400 2.4
500 3.2
Part B (Bending Moment)
Table 2 Bending moment with variation of load.
Bending Bending
Error
Load Load Moment Moment
Percentage
(g) (N) (Exp.) (Theory)
(%)
(Nm) (Nm)
0 0.2
100 0.9
200 1.7
300 2.4
400 3.2
500 4.1
EXPERIMENTAL RESULTS
Part A (Shear force)
1. Using the data in the Table 1, plot the bar chart for the shear force for the theoretical
and experimental case for each load case.
2. Calculate the percentage of error for each load case and hence determine the overall
percentage error.
Part B (Bending Moment)
1. Using the data in the table, plot a chart to compare the experimental and theoretical bending
moment for each case.
2. Calculate the percentage error for each case and hence, determine the average area.
5.0 DISCUSSION
For discussion, you should answer all questions as follows:
Part A (Shear force)
Analyze and interpret the results of this test. Comment on the differences between the
experiment and theoretical results.
List the main factors that affect the accuracy of the experimental results. Justify your answer.
Part B (Bending Moment)
Analyze and interpret the experimental and theoretical results. Comment the accuracy of
these results.
State/list the probable factors that affect the accuracy of the results. Suggest how the errors
may be eliminated or minimized.
6.0 CONCLUSION
Give your conclusion of this experiment work / report. Summarize its main findings.
