Que1.1. Define the term’ Structure’. Also bandy the structural rudiments. Answer Structure 1. A structure is a system of connected corridor used to support a cargo. exemplifications of structures in civil engineering are structures, islands and halls. 2. While designing a structure the mastermind must regard for its safety, aesthetic and utility also taking into consideration profitable and environmental constraints. Structural Elements The common structural rudiments are as follows 1. Tie rods 2. shafts 3. Columns 1. Tie Rods( or Bracing Struts) Tie rods or bracing struts are the structural members subordinated to tensile force. Tie rods are slender and are frequently chosen from rods, bars, angles or channels. Rod Bar Angle Channel Typicalcross-sections Tie rodFig.1.1.1. Tie rods. 2. shafts shafts are generally straight vertical members used primarily to carry perpendicular loads. ii. When the sampling varies, the ray is appertained to as phased or hunkered . shafts are primarily designed to repel bending moment. Bracket of Structures 1 – 4 C( CE- Sem- 5) Simply supported ray Cantilevered ray Fixed- supported ray nonstop ray 1.1.2. shafts. 3. Columns Columns are generally perpendicular and repel axial compressive loads. occasionally columns are subordinated to both an axial cargo and a bending moment, also these columns are known as ray columns. Que1.2. Explain the bracket of structures in detail. AKTU 2012- 13, Marks 05 Answer Bracket of Structures These can be classified as follows 1. On the Base of Structural Forms and Shapes Linear forms( Cadaverous structures). ii. Curvilinear forms( face structures). Linear Forms They’re articulated structures assembled with corridor conforming of direct rudiments, similar as bars and shafts, the connection between them being bolted or concentrated or welded. Linear forms are preferred for domestic, sanctioned, and educational purposes. The direct form is called cadaverous structures. a) Frame( b) Artificial chalet( c) Plate exemplifications Frame, high rise structure, stilt, artificial chalet, ground sundeck, plate,etc. ii. Curvilinear Forms Curvilinear forms as single realities substantially enthrall a space. b. These structures are idealized as nonstop system for structural analysis purpose. They’re 3- D structures and they’re also nominated as face structures. exemplifications Dome, shells, bends, lines, spherical members,etc. a) Dome( b) Arch( c) Spherical member w kN/ m 2. On the Base of Dominant Stress Conditions Livery stress forms. ii. Varying stress forms. Livery Stress Forms When the stress across a section is invariant over the depth of a member or over the consistence of a panel, such a form is called livery stress form. Example Cables, bends, band member, shellsetc. ii. Varying Stress Forms When the stress varies over the depth or consistence, from a maximum compressive stress on one face to a maximum tensile stress on the other, such a form is called varying stress form. Example shafts, rigid frames, crossbeams, platesetc. 3. On the Base of the Complexity of their Force Analysis shafts and trusses. ii. lines and bends. iii. Frames. iv. face structures. shafts and Trusses shafts and trusses are a form of structures. b. A simply supported ray, supported on a leg at one end and a comber at the other end is relatively stable and statically determinate, and transmits the external loads to the supports substantially through shear and moment. c. Some generally complex types of shafts are fixed end shafts and nonstop shafts. These shafts are statically indeterminate and can not be answered using equations of static equilibrium alone. a) Simple ray( b) Fixed end ray c) nonstop ray Compression Tension d) Stilt ii. lines and bends a. These two form of structures are used for long span. lines are generally flexible and carry their loads in pressure. c. The external loads aren’t applied along the axis of the string and accordingly string takes a form of defined slack. lines are generally used to support islands and erecting roofs. bends are characterized by high axial thrust and fairly low bending moment which affect from its distinguished shape as well as the vertical responses that developed at the support points. bends achieve their strength in contraction. bends must be rigid in order to maintain its shape. bends are used in ground structures, pate roofsetc. a) Arch( b) Cable structure iii. Frames Frames are composed of shafts and columns that are either leg or fixed connected. Frames are characterized by moment defying members at some or at all the joints. , this structure is generally If it has rigid commonconnections.indeterminate. Frames can be two or three dimensional. a) Artificial frame() Multi storey structure frame iv. face Structure a. A face structure is made of a material having veritably small consistence compared to its other confines. face structures may also be made of rigid material similar as corroborated concrete. c. They may be shaped as folded plates, cylinders or hyperbolic paraboloids and are appertained to as thin plates or shells. d. These structures act like lines or bends since they support loads primarily in pressure or contraction, with veritably little bending. a) Spherical shell( b) Hyperbolic paraboloids Que1.3. Define the term frame and explain what are the framed structure system and nonstop structure system? Answer 1. Framework A frame is the shell of the complete structure and it supports all intended loads safely and economically. 2. Framed Structure System Assemblage of members forming a frame to support the forces acting on it, is called the framed structure system. As frame, high- rise structure, stiltetc. 3. nonstop Structure System Assemblage of nonstop member like shells, pollsetc., are called nonstop structure system. As spherical members, space crafts, aircraftsetc. Que1.4. What do you understand by the term structural cargo? Explain different types of loads. Answer Structural cargo Structural cargo is consists of following loads 1. Dead Loads Dead loads are fixed to the structure and is substantially steady with time. Example Self weight of the structure, cabinetwork,etc. ii. Dead loads live permanently in the structure and are the introductory parameter for design in all structural systems. 2. Live Loads Live loads are the loads which are variable in nature, both in the time and magnitude. These loads are applied over and above the dead or fixed loads. They’re generally known as assessed loads. 3. Environmental Loads i. These loads are due to wind, earthquake, cataracts, landslidesetc., and caused by natural miracle. ii. These loads are substantially non deterministic because of misgivings associated with their circumstance, time and magnitude and terrestrial conditions. 4. Man- made Loads Man- made loads are caused by mortal conditioning. These loads are suchlike impact loads, blast loads, dynamic loadsetc. Types of Loads 1. Bracket of Loads on the Base of Direction in which Loads are Acting graveness Loads graveness loads are the dead loads, live loads, snow and ice loads because they always act vertically down. ii. Side Loads The loads which act horizontally as wind loads, earthquake loads and soil and hydrostatic pressures are known as side loads. iii. Directionless loads Thermal loads, loads due to misfit and blasting loads are known as directionless loads. 2. Bracket of Loads on the Base of Their Variation with Time stationary or Monotonic Loads Loads that don’t vary with time and always act in the same sense are known as monotonic or stationary cargo. illustration dead loads, construction loads, snow loads and earth pressureetc. ii. Cyclic or Dynamic Loads Loads that vary with time and change their sense are known as cyclic or dynamic loads. Example earthquake loads, impact loads, blast loads and machine convinced loads. Dynamic cargo sets the structure to joggle. Fatigue cargo is a special case of dynamic or cyclic cargo which is applied constantly on the structure for a long duration. illustration business and surge convinced loads. Que1.6. What do you mean by degree of freedom? Also explain the kinematic indeterminacy. AKTU 2012- 13, Marks 05 OR What do you understand by kinematic indeterminacy of structures? Explain in sufficient detail. AKTU 2013- 14, Marks 05 Answer Degree of Freedom 1. When a structure composed of several members which are subordinated to loads, the joints suffer deportations in the form of gyration and restatement. 2. The number of independent common relegation is called the degree of kinematic indeterminacy or the number of degree of freedom. Kinematic Indeterminacy 1. Degree of kinematic indeterminacy or number of degree of freedom is the sum of degree of freedom in gyration and restatement. 2. A joint in space can have six possible movements( 3 direct deportations, one along each reference axis and 3 reels, one about each reference axis) hence it has six degree of freedom. 3. In case of a two dimensional system, a free joint has three degree of freedom( Two restatement and one gyration) hence in case of two dimensional system any joint may have outside of 3 degree of kinematic indeterminacy. 4. The total kinematic indeterminacy of a structure represents the sum of all the possible relegation that colorful joints of the structure can suffer.
