Bob Johansson's Page

"HI:   I guess I'm thinking of a beam with depth and you are thinking of a flat panel which would be a layer in a composite, so here is my reference so we are comparing apples and apples.  I will try a calculation and post  it…"

"HI:   I have experienced similar problem discrepancies between my computer analysis and hand calculations which I used  to check my results on various projects.  Previously, I found the problem was the way I was contraining or holding…"

"Sorry, that was a typo   T = VQ/It   it was a bad hair day.   Mike probably has lots to say about shear stress because its his specialty.    "

"If the stress element is three dimensional then there would be horizontal shear in two horizontal directions providing for static equalibriaum."

"Looking at a stress element in a beam  loaded under vertical shear, there has to be a horizontal shear component to offset the vertical shear for static equalibrium to occur   "

"Are you asking about the meaning of the horizontal shear stress that exists in a beam? This is important in composite beams because each layer of the beam is fastened together and the strength of the fastening mechanisim has to be sufficient to…"

"I had the same sort of problems. Mike got it all fixed up for me. Its Monday morning so he will probably reply in an hour or two.   Bob"

"Email the code ( ID) to:  support@intact-solutions.com   Don't post the ID here"

"I think you just type SnS at the command prompt. It will work for a couple of weeks like that, then stop.   If you buy a license the you type in SnSActivate to get up and running.   Im not sure if you have to be connected to the internet…"

"Propeller design http://propdesign.weebly.com/index.html  "

"Air foild cross sections http://www.ae.illinois.edu/m-selig/ads/coord_database.html    "

"http://www.grc.nasa.gov/WWW/k-12/FoilSim/index.html    "

"A propeller blade is divided into sections and each section is analysed according to its cross sectional shape. To be accurate on the analysis you will have to determine the thrust coefficient for each section, and from that you can figure out the…"

"Without a way to apply a uniform paraboloic load distibution along the length of the propeller vane I would break the propeller up into sections along its length using split lines. Then I would calculate the load at the center of each area according…"

"Hi: The load distibution looks like it parabolic, since the tangential velocity of the propeller is directy propotional to the radius or distance from the hub; and the applied thrust force and drag is proportional to the velocity squared.  Scan…"