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DEPARTMENT OF MECHANICAL ENGINEERING

FACULTY OF ENGINEERING

NATIONAL DEFENCE UNIVERSITY OF MALAYSIA

NAME Assessments /Items CO1 CO2 CO3

GROUP /

SECTION

Data Collection

(CO1&2)

/5 /5 -

GROUP

MEMBERS 1.

2.

3.

4.

5.

Formula / Calculation

(CO1 &2)

/5 /5 -

LECTURER Data Analysis (CO2) - /30

DATE OF

EXPERIMENT

Discussion (CO3) /30

DATE OF

SUBMISSION

Conclusion (CO3) /10

PENALTIES Overall Impression

(CO1)

/10

TOTAL /20 /40 /40

REPORT RECIEPT (tear here)

NAME:MATRIC NO.:TITLE:DATE OF SUBMISSION:

TIME OF SUBMISSION:STUDENTS SIGNATURE:APPROVED BY:

EML 3822

LABORATORY III

STRUT BUCKLING

SOLID LABORATORY

Marks:

/100

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1.0 TITLE: STRUT BUCKLING (BUCKLING OF COLUMNS)2.0 OBJECTIVETo investigate the buckling behavior of pinned-pinned Strut using Eulers Formula.

3.0 INTRODUCTIONIn 1757, mathematician Leonhard Euler derived a formula that gives the maximum axial load

that a long, slender, ideal column can carry without buckling. An ideal column is one that is

perfectly straight, homogeneous, and free from initial stress. The maximum load,

sometimes called the critical load, causes the column to be in a state of unstable

equilibrium; that is, any increase in the load, or the introduction of the slightest lateral

force, will cause the column to fail by buckling.

4.0 APPARATUSThe test will be conducted using Buckling Test Machine, Strut Rig TQ SM105 MKII with

column of 550, 600, 700 and 750 mm length.

Refer to apparatus manual available in the Lab.

As the column is axially loaded, the dial indicator will measure the deflection in the

beam. The cross member that houses the indicator can be moved laterally to place

the indicator at the location on the column with maximum deflection.

The load is applied for a deflection increment of 0.5 mm until such maximum

deflection for each sample occur:

o L = 550 mm, max deflection = 5 mm.

o L = 600 mm, max deflection = 8 mm.

o L = 700 mm, max deflection = 11 mm.

o L = 750 mm, max deflection = 11 mm.

5.0 RESULTSRecord all results for Load (P) that causes the the 0.5mm incremental Deflection () from all

four samples. Show calculations for Critical Load, Critical Stress and Slenderness ratio.

6.0 ANALYSIS Plot graphs:

a. Load, P (N) vs Deflection. (From experiment only)

b. Critical Load, Pcr (N) vs Column Length.

c. Critical Stress, cr (N/mm2)

vs Slenderness Ratio.

For b and c, draw graphs plotted from the experiment and theoretically calculated

values.

Analyse and compare results with theories.

Compare the experimentally determine value for Pcr with the value obtained usingEulers formula.

Present and discuss the equations and the derivation of the equations that were

used to determine the calculated value of Pcr and the experimentally obtained value.

http://en.wikipedia.org/wiki/Mathematicianhttp://en.wikipedia.org/wiki/Leonhard_Eulerhttp://en.wikipedia.org/wiki/Mechanical_equilibriumhttp://en.wikipedia.org/wiki/Mechanical_equilibriumhttp://en.wikipedia.org/wiki/Leonhard_Eulerhttp://en.wikipedia.org/wiki/Mathematician

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7.0 DISCUSSION

Comment your experimental results.

Examine the formula with regard to the load-bearing ability of slender columns.

Explain irregularities/inaccuracy in results produced against theory.

Extra Questions:

Give two examples where strut buckling has to be taken into consideration during an

engineering design of a component or machine parts

What is the limitation (or acceptable limit) of applying Eulers Theory. Explain your

answer with appropriate graph.

Few assumptions were made in developing the column theory. What are those

assumptions and which assumptions cause the major difference between

experimental and theoretical results. Explain your answer.

8.0 CONCLUSION

List major conclusions or results of the experiment and indicate the measure of certainty of

the results. Include a few numerical results if appropriate.