The Mechanicals

Hydraulic & Fluid Mechanics Density/Mass density : mass/unit volume at standard temp and pressure. rho =M/V unit: kg /me Weight density/specific weight : weight /unit volume  at standard temperature and pressure. w=rho x g unit : N/me Specific volume : volume/unit mass of liquid  v=V/m unit : m3/ kg Specific gravity : it is defined as specific weight of liquid to specific weight of pure water at 4 degree C it has no unit Viscosity : it offers resistance to movement of one layer of liquid to another layer  Compressibility : properly change in volume to change in pressure. it is reciprocal of bulk modulus of elasticity. Surface tension : property of liquid which enables to resist tensile stress denoted by sigmaunit  : N/m Capalary : phenomena of rise /fall of surface in small tube held in liquid relatives. Pressure of liquid : When liquid contained in vessel it exerts at all points on side & bottom of vessel force per unit volume area calle

Important point of Strength of material Stress : P/A =N/mm2 Strain : Change in length / original length = No unit Hook's law = good for elastic limit Modulus of elasticity = linear stress/linear strain Poison ratio :  lateral strain / linear strain (Max. = 0.5) E = 210 kN/mm2 Strain roseter = used to measure liner strain. Max. stress at smaller end in tapper bar bolt pass through pipe both are tightly fitted with nut and washer so bolt in tension tube in compression bar cooled at -5 degree c it develop tensile stress. Energy stored in body = strain energy Total strain energy stored in body = Resilience Max. strain energy stored in body = Proof resilience Proof resilience / Unit volume = Modulus of resilience  Strain energy suddenly loaded = 4 x Gradually loaded  Contraflex point = bending moment change sign (overhanging beam)(simply supported beam) Shear force = 0, Bending moment = max Bending moment at fix end = max In pure bending = bending is constant, s