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0 exp no.3 torsion

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Muhammed Fuad Al-Barznji

Muhammed Fuad Rashid Petroleum Engineering Department at Koya University Mechanics of material Laboratory 2020

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Faculty of Engineering Petroleum Engineering Department Mechanics of material Laboratory, 2nd stage Experiment Name. Torsion Test Prepared by: Muhammed Fuad Rashid Ahmad Jalal Hasan Muhammad Hasan Aziz Safwan Tofiq Ameen Group: A Supervised by: Dr. Diyar

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2 Table of Contents Introduction................................................................................................................................3 TORSION TEST .........................................................................................................................3 WHY WE PERFORM A TORSION TEST? .....................................................................................4 Aim of the experiment ................................................................................................................5 Results and discussion.................................................................................................................6 References:...............................................................................................................................11

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3 Introduction TORSION TEST Torsion testing is a type of mechanical testing that evaluates the properties of materials or devices while under stress from angular displacement. Torsion testing can be split into two distinct categories: testing raw materials like metal wires or plastic tubing to determine properties such as shear strength and modulus, or functional testing of finished products subjected to torsion, such as screws, pharmaceutical bottles, and sheathed cables. The most common mechanical properties measured by torsion testing are:  Modulus of elasticity in shear  Yield shear strength  Ultimate shear strength  Modulus of rigidity in shear  Ductility

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4 WHY WE PERFORM A TORSION TEST? Many products and components are subjected to torsional forces during their operation. Torsion testing is necessary when engineers wish to change or update the materials used in these products. For example, the metal used in vehicle drive trains experiences a complex combined loading when in use, with torsion being the main component. An engineer trying to design a more fuel- efficient vehicle may need to change the material of the driveshaft in order to reduce vehicle weight. Torsional testing can help the engineer identify an appropriate material that will possess the required torsional strength while also contributing to the goal of light weighting. Many finished products are also subjected to torsional forces during their operation. Products such as biomedical tubing, switches, and fasteners are just a few devices subjected to torsional stresses in their everyday use. By testing their products in torsion, manufacturers are able to simulate real life service conditions, check product quality, verify designs, and ensure proper manufacturing techniques.

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5 Aim of the experiment The purpose of a torsion test is to determine the behavior a material or test sample exhibits when twisted or under torsional forces as a result of applied moments that cause shear stress about the axis. Also finding measurable values like Modulus of elasticity in shear and Yield shear strength and so on. Used to find The modulus of rigidity. And The general characteristics of the torque, angle of twist relationship.

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6 Results and discussion The general formula of torsion is 𝝉 = 𝚻𝝆 𝓙 T = torque or twisting moment, [N×m, lb×in] J = polar moment of inertia or polar second moment of area about shaft axis, [m4 , in4 ] τ = shear stress at outer fibre, [Pa, psi] r = radius of the shaft, [m, in] in the proceeded test the values of the specimens properties was obtained and calculated such as its radius in different dimeters and its polar moment of inertia also was calculated using the dimeters of the specimen. all this variables were uses to calculate the shear stress a round or by other mean the surface of the shaft, and the data which obtained was plotted and finally we obtained a two curves which;

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7 1-fisrt plot represents the shear stress acts on the round the shafts versus the different radius of the specimens.  Dimeter=𝟏𝟎𝒎𝒎  Radius = 𝟓𝒎𝒎  polar moment of inertia= 𝟗𝟖𝟏. 𝟐𝟓𝒎4 According to this plot which as we mentioned its between different radius which may be obtained from different specimens as are result we calculated the shear stress will act on the shaft, here as we observe here with increase the radius will also the shear stress acts on the shaft will increase and logically we can prove that for example when a tire made of wood rotates on ground first the surface the tire damages then after that its core due to friction of the ground which also makes a shear stress on the tire and this is due to the formula of shear stress on a shaft which equals; 𝝉 = 𝚻𝝆 𝓙 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0 5 10 15 20 25 30 35 40 shearstress Torque shear stress and torque

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8 So due to this equation the relation between the shear stress and the radius is proportional relation which means as increasing one values the other values increases to in the same ratio or different.

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9 2-the second plot represents the shear stress acts on surface of the shaft versus the polar moment of inertia.  D (Dimeter)=𝟏𝟎𝒎𝒎  T (Torque or twisting moment)= 𝟏𝟎𝟎 𝓝 ∗ 𝒎  J (polar moment of inertia)= 𝟗𝟖𝟏. 𝟐𝟓𝒎4 In this plot we can say that the relation between the torque and the shear stress is also a proportional relation which means as the torque of the shaft increases also the shear stress acts on the surface of the shat increase that is because the torque And this relation is due to the equation of shear stress which conclude torque which equals; 𝝉 = 𝚻𝝆 𝓙 -0.2 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 0.2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 raduis shear stress raduis and shear stress

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10 Conclusion: Many mechanical structures are subjected to torsion during their operations. By testing these materials used in these structures on torsion test, the manufacturers are able to simulate real life service conditions, check products quality, verify designs, and ensure proper manufacturing techniques as the shear stress, shear stress proportional limit, ultimate shear stress and the modulus of rigidity of these materials are known. Figure 1 Instron machine testing torsion experiment

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11 References: - co, i. (2019). What is Torsion Testing? - Instron. [online] Instron.in. Available at: https://www.instron.in/en-in/our-company/library/test- types/torsion-test [Accessed 25 Nov. 2019]. - Types, T. (2019). Torsion Test. [online] Testresources.net. Available at: https://www.testresources.net/applications/test-types/torsion-test/ [Accessed 25 Nov. 2019]. - Hibbeler, R. C. "Mechanics of Materials", Prentice-Hall, 7th Edition.

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0 exp no.3 torsion

  • 1. Faculty of Engineering Petroleum Engineering Department Mechanics of material Laboratory, 2nd stage Experiment Name. Torsion Test Prepared by: Muhammed Fuad Rashid Ahmad Jalal Hasan Muhammad Hasan Aziz Safwan Tofiq Ameen Group: A Supervised by: Dr. Diyar
  • 2. 2 Table of Contents Introduction................................................................................................................................3 TORSION TEST .........................................................................................................................3 WHY WE PERFORM A TORSION TEST? .....................................................................................4 Aim of the experiment ................................................................................................................5 Results and discussion.................................................................................................................6 References:...............................................................................................................................11
  • 3. 3 Introduction TORSION TEST Torsion testing is a type of mechanical testing that evaluates the properties of materials or devices while under stress from angular displacement. Torsion testing can be split into two distinct categories: testing raw materials like metal wires or plastic tubing to determine properties such as shear strength and modulus, or functional testing of finished products subjected to torsion, such as screws, pharmaceutical bottles, and sheathed cables. The most common mechanical properties measured by torsion testing are:  Modulus of elasticity in shear  Yield shear strength  Ultimate shear strength  Modulus of rigidity in shear  Ductility
  • 4. 4 WHY WE PERFORM A TORSION TEST? Many products and components are subjected to torsional forces during their operation. Torsion testing is necessary when engineers wish to change or update the materials used in these products. For example, the metal used in vehicle drive trains experiences a complex combined loading when in use, with torsion being the main component. An engineer trying to design a more fuel- efficient vehicle may need to change the material of the driveshaft in order to reduce vehicle weight. Torsional testing can help the engineer identify an appropriate material that will possess the required torsional strength while also contributing to the goal of light weighting. Many finished products are also subjected to torsional forces during their operation. Products such as biomedical tubing, switches, and fasteners are just a few devices subjected to torsional stresses in their everyday use. By testing their products in torsion, manufacturers are able to simulate real life service conditions, check product quality, verify designs, and ensure proper manufacturing techniques.
  • 5. 5 Aim of the experiment The purpose of a torsion test is to determine the behavior a material or test sample exhibits when twisted or under torsional forces as a result of applied moments that cause shear stress about the axis. Also finding measurable values like Modulus of elasticity in shear and Yield shear strength and so on. Used to find The modulus of rigidity. And The general characteristics of the torque, angle of twist relationship.
  • 6. 6 Results and discussion The general formula of torsion is 𝝉 = 𝚻𝝆 𝓙 T = torque or twisting moment, [N×m, lb×in] J = polar moment of inertia or polar second moment of area about shaft axis, [m4 , in4 ] τ = shear stress at outer fibre, [Pa, psi] r = radius of the shaft, [m, in] in the proceeded test the values of the specimens properties was obtained and calculated such as its radius in different dimeters and its polar moment of inertia also was calculated using the dimeters of the specimen. all this variables were uses to calculate the shear stress a round or by other mean the surface of the shaft, and the data which obtained was plotted and finally we obtained a two curves which;
  • 7. 7 1-fisrt plot represents the shear stress acts on the round the shafts versus the different radius of the specimens.  Dimeter=𝟏𝟎𝒎𝒎  Radius = 𝟓𝒎𝒎  polar moment of inertia= 𝟗𝟖𝟏. 𝟐𝟓𝒎4 According to this plot which as we mentioned its between different radius which may be obtained from different specimens as are result we calculated the shear stress will act on the shaft, here as we observe here with increase the radius will also the shear stress acts on the shaft will increase and logically we can prove that for example when a tire made of wood rotates on ground first the surface the tire damages then after that its core due to friction of the ground which also makes a shear stress on the tire and this is due to the formula of shear stress on a shaft which equals; 𝝉 = 𝚻𝝆 𝓙 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0 5 10 15 20 25 30 35 40 shearstress Torque shear stress and torque
  • 8. 8 So due to this equation the relation between the shear stress and the radius is proportional relation which means as increasing one values the other values increases to in the same ratio or different.
  • 9. 9 2-the second plot represents the shear stress acts on surface of the shaft versus the polar moment of inertia.  D (Dimeter)=𝟏𝟎𝒎𝒎  T (Torque or twisting moment)= 𝟏𝟎𝟎 𝓝 ∗ 𝒎  J (polar moment of inertia)= 𝟗𝟖𝟏. 𝟐𝟓𝒎4 In this plot we can say that the relation between the torque and the shear stress is also a proportional relation which means as the torque of the shaft increases also the shear stress acts on the surface of the shat increase that is because the torque And this relation is due to the equation of shear stress which conclude torque which equals; 𝝉 = 𝚻𝝆 𝓙 -0.2 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 0.2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 raduis shear stress raduis and shear stress
  • 10. 10 Conclusion: Many mechanical structures are subjected to torsion during their operations. By testing these materials used in these structures on torsion test, the manufacturers are able to simulate real life service conditions, check products quality, verify designs, and ensure proper manufacturing techniques as the shear stress, shear stress proportional limit, ultimate shear stress and the modulus of rigidity of these materials are known. Figure 1 Instron machine testing torsion experiment
  • 11. 11 References: - co, i. (2019). What is Torsion Testing? - Instron. [online] Instron.in. Available at: https://www.instron.in/en-in/our-company/library/test- types/torsion-test [Accessed 25 Nov. 2019]. - Types, T. (2019). Torsion Test. [online] Testresources.net. Available at: https://www.testresources.net/applications/test-types/torsion-test/ [Accessed 25 Nov. 2019]. - Hibbeler, R. C. "Mechanics of Materials", Prentice-Hall, 7th Edition.
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