Que2.2. What are colorful types of trusses? Explain with the help of neat sketches.
Answer The colorful types of the trusses are described as follows Roof Trusses 1. Roof trusses are frequently used as part of an artificial structure frame, as shown inFig.2.2.1. Then, the roof cargo is transmitted to the stilt at the joints by means of a series of purlins. 2. The roof stilt along with its supporting columns is called as fraudulent. 3. naturally, roof trusses are supported either by columns of wood, sword, or corroborated concrete, or by masonry walls. 4. To keep the fraudulent rigid, and thereby able of defying vertical wind forces, knee braces are occasionally used at the supporting columns. 5. The space between conterminous bents is called a bay. kudos are economically spaced at about4.6 m for spans around 18 m and about6.1 m for spans of 30m. 6. kudos are frequently tied together using slant bracing in order to maintain severity of the structure’s structure. 7. Trusses used to support roofs are named on the base of the span, the pitch, and the roof material. 8. Some common types of trusses are scissors band, the Howe and Pratt stilt, Addict stilt or Fink truss, Warren truss, Sawtooth truss, Bowsting stiltetc. Bridge Trusses 1. The main structural rudiments of a typical ground stilt are shown in Fig. . Then it’s seen that a cargo on the sundeck is first transmitted to stringers, also to bottom shafts, and eventually to the joints of the two supporting side trusses. 2. The top and nethermost cords of these side trusses are connected by top and bottom side bracing, which serves to repel the side forces caused by wind and the sideway caused by moving vehicles on the ground. 3. fresh stability is handed by the portal and sway bracing. 4. As in the case of numerous long- span trusses, a comber is handed at one end of a ground stilt to allow for thermal expansion. 5. A many of the typical forms of ground stilt Pratt, Howe and Warren trusses are typically used for spans up to 61 m in length. 6. For larger spans, a stilt with a polygonal upper cord, similar as the Parker stilt, is used for some savings in material. Structural Analysis 2- 5 C( CE- Sem- 5) 7. The topmost frugality of material is attained if the inclinations have a pitch between 45 ° and 60 ° with the vertical. 8. still, also for spans lesser than 91 m, the depth of If this rule ismaintained.the stilt must increase and accordingly the panels will get longer. 10. This result in a heavy sundeck system and, to keep the weight of the sundeck within tolerable limits, subdivided trusses has been developed.
Que2.3. What are different styles of analysis of trusses? Explain any bone in detail.
What are the styles available for the analysis of trusses? Explain.
Answer Different styles of Analysis of Trusses To dissect a statically determinate band we’ve following two styles 1. system of joints. 2. system of sections. 1. system of Joints i. In system of joints, the principle used is, if a stilt is in equilibrium, also each of its joint must also be in equilibrium. ii. common analysis should start at a joint having atleast one given force and atmost two unknown forces. , member will be in contraction and viceversa, If a force is pushing on the leg. iv. During result of a stilt always assume the unknown member force amusement on the joint’s free body illustration to be in pressure. v. If our supposition is correct also result will be positive for the member. vi. Now use the correct magnitude and direction of force on posterior joint’s free body illustration. Procedure to Analyze First calculate the external support responses by drawing the free body illustration of the entire stilt. ii. Draw free body illustration of a joint having at least one given force and atmost two unknown forces. iii. Assume the unknown member force as tensile in nature i.e., force is pulling the joint. iv. Now exposure of X and Y axes are to made similar that forces on the free body illustration can be fluently resolved into their x and y factors. Apply two force equilibrium equations ΣFx = 0 and ΣFy = 0. break these two equations to get unknown member force and also corroborate their correct directional sense. vi. Continue to dissect each of the other joints, where again it’s necessary to choose a joint having atleast one given force and atmost two unknown forces. 2. system of Sections , also the If the forces in only a many members of a stilt are to befound.method of sections generally used to gain these forces. ii. The system of section involves passing an imaginary section through the stilt, therefore cutting it into two corridor. iii. Each of the two corridor must also be in equilibrium. iv. Try to elect the insulated portion of the stilt haven’t further than three unknown force members. v. Since only three independent equilibrium equations are present as Fx = 0, Fy = 0 and M = 0. Procedure to Analyze originally cut or choose a section of stilt where forces are to be determined. ii. opting the section, it may first be necessary to determine the stilt’s external responses. iii. Draw the free body plates of the named or sectioned stilt having the least number of forces on it. iv. Let the member force as tensile in nature, i.e., pulling on the member common leg. Take totality of the moment about a point that lies at the crossroad of the lines of action of two unknown forces. , forces may be added If two of the unknown forces areparallel.perpendicular to the direction of these unknowns to determine directly the third unknown force. Que2.4. bandy the conception of internal stability of a stilt. Answer Internal Stability 1. Internal stability of a stilt can be checked by examination of the arrangement of its members. 2. If each joint is held fixed so that it can not move in a rigid body sense with respect to the other joints, also the stilt will be stable. 3. A simple stilt will always be internally stable. 4. If a stilt is constructed so that it doesn’t hold its joints in a fixed position, it’ll be unstable or have a critical form. 2.4.1( a) is internally stable. InFig.2.4.1( b) no fixity is handed between joints B and F or G and C, so the stilt will collapse under cargo. Internal Stability of a emulsion Stilt 1. For checking the internal stability of a emulsion stilt we need to identify the way in which the simple trusses are connected together. 2. InFig.2.4.2, when an external cargo is applied to joint D, E or F can beget the stilt DEF to rotate slightly i.e., internally unstable. Internal Stability of a Complex Truss 1. It may not be possible to tell about internal stability of a complex stilt whether it’s stable or unstable. 2. Flash back that, still if a stilt is unstable, it doesn’t count whether it’s statically determinate or indeterminate. The use of an unstable stilt is always avoided.
Que2.5. Explain the conception of Zero- Force Members in a stilt.
Answer Concept of Zero- Force Member 1. The member that supports no lading are nominated as zero- force members. 2. Zero force members are used to simplify the stilt analysis using the system of joints. 3. Zero force members are necessary for the stability of the stilt during construction. 4. Zero force members are used to give support if the applied lading is changed. 5. Zero force members do in following two cases i. If no external cargo is acting at a joint and the members joined at this joint are at any angle also force in both of the members must be zero in order to maintain equilibrium. Analysis of Trusses 2 – 8 C( CE- Sem- 5) ii. If no external force is acting on a joint having three members for which two of the members are collinear, the third member is a zero force member. Then F3 = 0, as no force is acting in y- direction to balance it.