Hi everyone,
I am working on a weld procedure to weld A-516 Gr70 (P1 G2 ASTM material) to a forged 1030/1035 tube. 1030 and 1035 are not classified, so my procedure must use 1030 or 1035 to qualify it. My problem is I have been unable to find any 1030 or 1035 tube that is large enough. We...
This may seem like an odd question, but I have always operated under the assumption that hydraulic cylinders should be designed and manufacturered to ASME Section VIII code since I consider them to be pressure vessels. I have worked for a cylinder manufacturer and we desgined per VIII code, but...
Hello everyone,
I am relatively new to SW and a complete newby when it comes to top-down assemblies. I have been reading up on them online and have come to the conclusion that my best bet is to create a layout drawing of my assembly (I can represent it in a single layout view in 2d. I can...
Hello everyone,
I am driving myself crazy trying to figure out how to assign tolerances in the parameter table. I have the dimension, name, etc, and I can tell Inventor how to display the part (min, max, middle of tolernace). However, I need to easily define tolerances (ie without right...
Hello everyone,
I have a question that hopefully you guys can help me with. I am a mechanical engineer and like to dable in some electrical stuff, but am no good at it. Anyway, I need to re-build a small DC motor. Here is the scenerio:
I have a vehicle modified for a wheelchair that uses a...
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I have an interesting problem (I think so anyway). I am trying to determine the section modulus of a part that I have and am having some trouble. The cross-sectional shape of the part is basically a rectangular tube with a vertical dividing wall in the middle (it is actually...
Hello all.
I have a question about stress concentration factors in a ductile pin. In order to calculate the pin diameter in perfect shear, I have always used the crossectional area and load to determine the average shear stress in the pin and design to that.
I know there is some increase in...
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I am been running this situation through my head and am having trouble with it. Lets say I have two beams, say sqaure tubes of the same dimensions (length and everything), but different material. One is A36 and the other is heat treated 4140. Both have the same modulus of...
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I am working on some thick walled pressure vessels and would like to apply the Roark equation for a thick walled for this case and noticed something odd.
Until now, we have always used the Barlow equation with a hefty safety factor, thick walled or not, but now we are moving on...
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Is there a way to estimate the allowable bearing stress of a metal if the typical properties (UTS, YS, E, ect.) are known? I know the bearing stress is usually much higher than the yield, and a little higher than the UTS, but I would like to know for sure.
If this is not...
Hello everyone,
We are working with 4130 for a part we are building and need to reach a Charpy impact result of at least 25 ft-lbs (avg.). We are falling way short (we are at 10, 4, 5...). From what I understand, results have been improved in the past by heat treating. Heat treating seems...
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I have searched and searched this site as well as the web for the relationship between shear and tensile strengths of metals. I typically use 1/2 of tensile to estimate the shear strength. However, I remember a professor telling us that there is a definate relationship that...
Hello Everyone,
I have a question about thread shear/failure. I have always based my calculations on assuming 2 to 3 threads handle the full load placed on whatever threaded fastener I am using. A bolt shank should fail due to tension before the threads fail by design (typically).
Now, fine...
Hello everyone,
I am learning inventor and have a question about the stress analysis portion. I have a simply supported beam I would like to run an analysis on and am having trouble defining the fixed constraint. I need a pin type constraint, but I can only seem to define a full face...
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I am designing a bracket to put a bolted link in double shear. I want to make sure the bracket thickness is great enough such that the bolt shears before the hole in the bracket elongates. It seems I remember that a good estimate of bearing surface to calculate stress is 1/3...
Hello everyone,
Is there a MDT alternative? From what I can tell, it is essentially a plug-in for autocad that is created by Autodesk. There are many plug-in type softwares that are written by 3rd parties. Shipconstructor comes to mind b/c some guys here at work use it. Since Autodesk has...
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I am trying to cut the speed of a 12 VDC motor by 3, or 4 if I can get it that low. The simple answer is, send it 3 vdc. But, the motor's max current is 20 amps, so I need to know a cheap and easy way to do this. Here is the setup:
Motor will be turned on using a...
I am running inventor 9. I do not use it much, I mainly use mechanical desktop 2005 (have not upgrade b/c I want to keep MDT). I use inventor for FEA only. I wanted to run a FEA a couple of days ago but when I try to import a MDT file, open an inventor part, or create a new part in inventor...
Hello everyone,
I am working on an automotive project where I would like to run 2 alternators. The first alternator will be the stock one and drive all of the stock/factory electronics. The second will supply power to a lot of aux electronics.
There are a lot of reasons I want/need to run...
Hi everyone, I have what may be a really dumb question. A dc motor controller controls the speed of the motor by adjusting the output voltage. This voltage is usually linearly related to the speed of the motor. The needed current is also supplied to the motor through the controller (assuming...
