FATIGUE CLASS NOTES FOR MECHANICAL ENGINEERING It is the failure of material under reversal of stress. Fatigue reduces the strength of a material. Notable Fatigue Failures Versailles train disaster The 1862 Hartley Colliery Disaster De Havilland Comet crash Alexander L. Kierland oil platform capsizing The 1919 Great Molasses Flood The 1948 Northwest Airlines Flight…
STRESS CONCENTRATION FACTORS CLASS NOTES FOR MECHANICAL ENGINEERING It is increase in stress due to a discontinuity in a body under loading. Discontinuities are quite common. Stress increase depends on the type and extent of a discontinuity. Stress increases due to the following discontinuities. (i) Key seat in a shaft (ii) Threads on…
DISCONTINUITY STRESS CLASS NOTES FOR MECHANICAL ENGINEERING There are various types of discontinuities. A designer first establishes the type of discontinuity. He calculates the discontinuity stress. These stresses are considered in the design of pressure vessels /pipes and structures. Two types of discontinuities (i) Gross structural discontinuity (ii) Local structural discontinuity Gross Structural Discontinuity A…
ELLIPSE OF STRESS & STRAIN CLASS NOTES FOR MECHANICAL ENGINEERING Ellipse of stress finds resultant stress and the angle of obliquity. In 2-D, it is ellipse of stress . In 3-D it is ellipsoid of stress. Actually all bodies are 3-D. All stress systems are also 3-D. But to make study easy to understand,…
MOHR’S STRESS CIRCLE CLASS NOTES FOR MECHANICAL ENGINEERING Every item in nature is under complex loading. Hence, it is under complex stresses. But a material fails in a simple manner. It may fail in simple tension/ compression/shear/strain energy/simple strain/shear strain energy. Mohr’s Stress Circle is a graphical method to determine simple stresses and strains from…
PRINCIPAL STRESSES INTRODUCTION CLASS NOTES Every object in nature is under complex loading. Hence it is under complex stresses. But failure occurs in a simple mode. It may be in simple tension, simple compression or simple shear. Hence convert complex stresses into simple stresses. Simple stresses are principal stresses. To achieve this, use analytical or…