STRESS ANDS TRAIN: Objectives: Study this concept with the following objectives: To understand the concept of ‘stress and strain’. To know different types of ‘stress and strain’. Unit: The SI unit of stress is "Newton per metre square" and The CGS unit of stress is "dyne per centimeter squre". Longitudinal stress. Volume or Bulk stress. Tangential or shearing stress. Normal stress: If the stress is normal to the surface, it is called normal stress. Stress is always normal in the case of a change in length of a wire or in the case of change in volume of a body. Longitudinal or linear stress: When a normal stress changes the length of a body, then it is called longitudinal stress. Or If the forces are applied along the length of the body then the stress is known as longitiudinal stress. Longitudinal stress = F/A , Where F is the deforming force acting on an area 'A' of the body. Here we can see, cable under tension being stretched by forces acting at its ends. Volume or Bulk stress: When a normal stress change the volume of a body, then it is called volume stress. Here we can see the example, When a body submersible is immersed in a fluid, the force at any point is normal to the surface of the submersible and the magnitude of the force on any small area is proportional to the area, i.e, the submersible is under the action of a pressure, P. Tangential or shearing stress: When the stress is tangential to the surface due to the application of force parallel to the surface, then the stress is called tangential stress. Summary: Moduli of elasticity: Objectives: The objective is understand the concept of ‘Moduli of elasticity’. The modulus of elasticity of a body is the magnitude of stress to be applied to produce unit strain. Corresponding to the three types of strain, there are three moduli of elasticity. Young’s modulus, corresponding to longitudinal strain, Bulk modulus, corresponding to volume strain, and Rigidity modulus, corresponding to shearing strain. Let us study the three types details: Young’s Modulus: Within the elastic limit, the ratio of longitudinal stress to longitudinal strain is called Young’s modulus 7 Active Technology Solutions Pvt.Ltd. is an educational 3D digital content provider for K-12. We also customize the content as per your requirement for companies platform providers colleges etc . 7 Active driving force "The Joy of Happy Learning" -- is what makes difference from other digital content providers. We consider Student needs, Lecturer needs and College needs in designing the 3D & 2D Animated Video Lectures. We are carrying a huge 3D Digital Library ready to use. For more information: http://www.7active.in http://www.sciencetuts.com Contact: 040-64501777 / 65864777 9700061777

• published: 05 Aug 2014
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