GREG: You are correct, I do not need 1 mm accuracy. The name "PERRYMAN" implies that the course is defined, perhaps in a spec, or std, or some other document. I realize that the "actual course" and the "defined course" can, and probably vary. I just want to find out how the course is...
CLOA AND GREG: Thank you for the your time and effort to respond, I sincerely appreciate it. The website listed by Cloa does not give the level of definiiton for which I am looking. For example is the profile flat or sinusoidal or somewhere in between. Greg, I did Email NATC asking for this...
HELLO ALL: Vehicle road testing can be done over predefined road profiles. The Perryman Profiles are often used. I am trying to find the definition of the Perryman Profiles. Does anyone have the profiles for the Perryman 1,2,3,4 road courses? I have searched the internet and have been...
JAE:Thank you for your response. The bending is about the flat side, as you noted. I understand your concern about space but I wanted someone to work the problem, in detail, and then scan and E-mail the results to me. I have the textbooks and I am muddleing through them But I would like...
JAE: Thank you for your response. You are correct. The 8" leg is flatbar that is 2" wide and .375" thick. The moment of inertia is:
(1/12)*(2)*(.375^3) =.0088
This is part of a small bracket that fits on the front of a vehicle and I am trying to determine the loads and stresses involved...
HELLO ALL: It has been over 30 years since I have worked witn the moment distribution . I am really rusty. By the way this is not a homework problem this is a real world problem. Here is the problem I am trying to solve.
A simple 2 dimensional frame with 8" legs and an 11 inch top cross...
HELLO ALL: Here is my question:
A bus (40000#) hits a auto (4000#) in the rear end at a low speed (10 mph) The strucural supports for the bike rack on the bus are deformed plastically. Is there a way to calculate/estimate the force on each of the two brackets?
Cordially
Dave
THANK YOU ALL FOR YOUR RESPONSES.
UNCLESYD: I do not have the specification or the plating procedure. The environment is just ambient conditions.
TXMEEN: The applied load is a shear load. A .125: X .5" aluminum bar with six .190" holes is positioned under the head and the screw...
RON: Thank you for your reply. There was a failure of six of these screws simultaneously. There is no information about other screw failures in similar systems. It is believed that in service these screws loosened and ultimately failed. The failures occured approximately 0.5 inches below...
HELLO ALL: Attached are two images of a 10-32 zinc plated steel screw that failed under a sidewise load. The load was applied under the head and the screw broke at the top of the threads in a rivnut. The part that bothers me is the hole in the middle of the screw that is seen in the endview...
HANDLEMAN: Thank you for your response. I did not give specific numbers becasue I was looking for a solution that would be in general form. I was remiss in not stating that.
Would you please give one or two sources for the numerical method I will need?
Thank you again for your quick...
HELLO ALL: This is a real problem. A uniform rectangular flat steel plate hinged on one side is held at an angle, theta (90<theta>0). The only force acting is earth's gravity. The plate is suddenly released and allowed to fall under th influence of gravity to the horizontal position. ignore...
DEAR UFJ:
For 1) I assume that 1 and 2 are sine vibrations and the G value is peak to peak. Make sure you know how your acceleroometers are calibrated. Othwise you could be off by 1.414. The 30 hz vibration has a slightly smaller displacement than the 13 hertz but the 13 hz is for a longer...
ROCKETMOTOR: To arrive at the displacement is easier to show than to explain but here gos. The PSD has the units of G^2rms/Hz. The PSD value .03 or .06 in this case is the average of all the peaks around the center frequency (usually +/- 1 db).
1. Take the square root of the G^2 rms term...
ROCKETMOTOR: In general the lowest frequency will have the highest displacement. Assuming the PSD values are in G^2 rms/Hz the approximate amplitude at 3 hz is around .25 g's peak. This corresponds to a peak displacement of about 600 mils or 0.6 inch peak or 1.2 inches peak to peak. At 20 Hz...
