What is influence line in structure?
An influence line for a given function, such as a reaction, axial force, shear force, or bending moment, is a graph that shows the variation of that function at any given point on a structure due to the application of a unit load at any point on the structure.
How do you calculate influence?
Add up your quality factors, add up your impact factors, and then multiply the two sums. Start by collecting the data and establishing your base line. Monitor the change in your influence metric and analyze the impact of each factor on the score.
Why do we consider moving loads to a structure?
A moving load is a load that moves over a given distance of a structural supporting system. A moving load is considered in the structural calculation by defining several load cases. In this case, each load case reflects a specific load position of the moving load in the structural system.
What is the minimum imposed load on roof trusses as per IS code?
What is the minimum imposed load on roof trusses as per IS code? Explanation: As per IS 875, the minimum imposed load on roof truss should be 0.4 kN/m2. For sloping roof upto 10˚, the imposed load is taken as 0.5 kN/m2 if access is not provided and 0.75 kN/m2 if access is provided. 9.
What are the three types of beams?
What are the types of beams based on support conditions?
- Simply supported beam.
- Fixed beam.
- Cantilever beam.
- Continuous beam.
What is the use of influence line diagram?
The most important use of influence line is finding out the location of a load for which certain response will have a maximum value. For example, we may need to find the location of a moving load (say a gantry) on a beam (say a gantry girder) for which we get the maximum bending moment at a certain point.
How are influence lines used in structural analysis?
Influence Lines Influence line is the graphical representation of the response function of the structure as the downward unit load moves across the structure. The ordinate of the influence line show the magnitude and character of the function.
Which is the best definition of an influence line?
Influence lines can be defined as a graph whose ordinates show the variation of the magnitude of a certain response function of a structure as a unit load traverses across the structure.
How to draw an influence line for a beam?
Step 1. At the position of support B (point B ), plot an ordinate +1. Step 2. Draw a straight line connecting the plotted point (+1) to the zero ordinate at the position of support C. Step 3. Continue the straight line in step 2 until the end of the overhangs at both ends of the beam. The influence line for By is shown in Figure 9.5b.
Why are influence lines so difficult to draw?
It is very important to emphasize the need for students to fully grasp the afore-stated definition, since most of the confusion and difficulty encountered when drawing influence lines stems from a lack of understanding of the difference between this topic and the bending moment and shearing force topics detailed in chapter four.