Mechanical blog

What is the difference between isotropic and homogeneous material? In homogeneous material the composition is same throughout and in isotropic material the elastic constants are same in all direction. Explain the difference between the points of inflection and contra flexure? At points of inflection in a loaded beam the bending moment is zero and at points of contra flexure in loaded beam the bending moment changes sign from increasing to decreasing. What is the difference between proof resilience and modulus of resilience? Proof resilience is the maximum strain energy that can be stored in a material without permanent deformation. Modulus of resilience is the maximum strain energy stored in a material per unit volume. What is the difference between column and strut? Both column and strut carry compressive load. Column is always vertical but strut as number of structure could carry axial compressive load in any direction. What are killed steals and what for these are ...

1. What is the difference between isotropic and anisotropic materials? If a material exhibit same mechanical properties regardless of loading direction, it is isotropic ie .homogeneous cast materials . Materials lacking this property are anisotropic. 2. what are orthotropic materials?. It is a special class of anisotropic materials which can be described by giving their properties in three perpendicular directions. 3. Explain the effects of alloying chromium and  nickel in stainless steel? Addition of nickel and chromium increases the tensile strength and increase in resistance to corrosion takes place. 4.What are the principal constituents of brass? Principal constituents of brass are copper and zinc. 5.What is curie point? Curie point is the temperature at which ferromagnetic materials can no longer be magnetised by outside forces. 6.Specific strength of materials is very high when they are in fibre size but lower when they are in bar for...

Abrasive A natural or artificial materials such as sandstone,emery, aluminium oxide or silicon carbide. Acid A chemical added to oil or fuel to increase it's effectiveness and obtain desirable qualities. Adhesives Materials or compositions that enable two surfaces to join together. An adhesive is not necessarily a glue which is considered to be a sticky substance since many adhesives are not sticky. Aggregate Small particles such as powderes that are used for powder metallurgy, that are loosely combined to form a whole also sand and rock as used in concrete. Allotropic metals Metals which exist in one lattice form over a range of temperature but at a certain temperature the lattice form changes to another type which is stable over another temperature range. Alloy A substance having metallic properties and is composed of two or more chemical elements, of which at least one is metal. Alloy steel Steel containing significant quantities of alloying...

Absolute humidity The weight of the water vapour which is associated with unit quantity of air. Absorber: A device for absorbing a refrigerant, a low side element in an absorption system. Absorption refrigeration system: One in which the refrigerant as it is absorbed in another liquid, maintains the pressure difference needed for successful operation of the system. Absorptivity Ability of a material to absorb heat. Accumulator A steel shell partly filled with liquid refrigerant, the space above which is maintained by the compressor at a pressure corresponding to the required refrigerant temperature. The shell is placed in a suction line for separating liquid entrained in suction gas. Actuators Secondary control mechanisms which function in response to the requirement of the primary group in actually controlling some part of the refrigeration system. ADIABATIC COMPRESSION Compression of a vapour or gas in such circumstances that there is insufficient time for an...