Share
Explore BrainMass

Cantilever Beam Deflection

A problem is needed using microsoft visual C++
to do the following.

Problem Description:
For your strength of materials course you wilii write a single program using control structures(including nested loops)and file I/O to explore the deflection of a cantilever beam with a point load at the free end. This is to be on the base on the equation for the eleastic curve of the form:

y=P/(EI)*(x(cubed)-3Lx(squared))
xcubed is x to the 3rd power and x sqaure is x to the 2nd power

Where y is the vertical deflection from the neutral axis-counterline-(inches,negative downward),P is the point load in pounds (lbs.,positive downward), x is the distance from the mounting point of the beam(inches), and L is the lenght of the beam (inches). Other properties of the beam that reflect its resistance to bending are E, the Modulus of Elasticity(psi or ibs/in sq), increasing for stronger materials) and I , the Moment of Inertia(inches to the 4th power, increasing for sturdier beam cross-sectional shapes). we will assume that the length is short enough that the weight of the beam itself may be safely ignored.

The program should offer the user the opportunity to perform one of two tasks then repeat or exit. The simplest approach with respect to analysis, design and testing is to treat each task as a separate small problem- with a simple wrapper around them to support user selection:
1. Read in a user supplied date file containing results from a lab experiment which measured actual deflection in a beam. The text file is of the form with E,I,L(in feet!!), and load P on each of the first four lines. This header is followed by the x,y data pairs (both in inches, number not known in advance!), one set per line with evenly spaced columns.
For each data point, output the current values, the theoretical value of y calculated from the formula for the elastic curve and the error between the two y values as a percentage of the theoretical value- on the same line. NOTE:At the end of the report display all info for the data point with the greatest discrepancy(plus or minus)<-this is the error, NOT the deflection. Send this output to the screen AND a user-specified file with a report header with your name and project info, listingand explaning the values from the top of the data file and the tabular data in cleanly formatted columes with headers, and consistent spacing and precision. Show enough decimal places.
THE DATA FILE PROGDATA.TXT IS SHOWN BELOW

2.Construct a table of deflections under various loads for a user-specified beam with E,I and L. This report will have x position information (user-specifies number of steps going down the page and the deflections calculatedat that same location for varing loads across the page in the same row. YOU MUST USE NESTED LOOPS.
let the user give a starting and ending loads for the interval to explore and offer him the choice of incrementing the load by 1,2,5,10 lbs(he will choose one) Print a header with all data (yours and the beam's), then nicely formatted columns with headers ( the load for that column-hint: use a loop here too), Again, print output to both the screen and a user specified file.

For testing purposes use values for the beam of:
Modulus of Elasticity E=29*10(to the 6th power)psi
Moment of Inertia I=82.8 Inches to the 4th power
Length L=12 ft( remember conversion to inches!)
# Steps foe x:15
Loads:from 280 to 320 lbs in steps of 10 lbs.

All input prompts and outputs should indicate the approprate units-BUT units should NOt be repeated in tabular output and should instead specified up in the report header.
Also, exit() the program if the values are entered from the user (or file) that would cause division by zero.
After solving a problem the program should display the main menu again and keep running until the user chooses to exit.

PROGDATA.TXT

29000000.0
82.8
12.0
300.0
0.000000 0.000000
9.600000 -0.000822
19.200000 -0.003119
28.800000 -0.007126
38.400000 -0.012091
48.000000 -0.018069
57.600000 -0.025788
67.200000 -0.035042
76.800000 -0.044516
86.400000 -0.054040
96.000000 -0.063109
105.600000 -0.077264
115.200000 -0.087870
124.800000 -0.100241
134.400000 -0.110278
144.000000 -0.125321

this date file is pulled from notepad.

Solution Preview

Hi,
<br><br>I've developed two codes in c++ according to your requirements.
<br><br>You check, whether they fulfill your requirements or needed further modifications.
<br><br>
<br><br>NOTE: The ...

Solution Summary

Cantilever Beam Deflection is emphasized.

$2.19