Excellent video!!!! It will be good as to complete this video with some calculations for the thickness of the bracket. The calculation of the thickness t as per the the actual loading strength LS = Mc *t/2 /( 1/12*b *t^3) where Mc = P*Y as per your diagram...if Allowed LS /(3*LS) -1 ...is negative...you will increase the thickness...(I'm assuming a safety factor of 3).
Thank you for your kind words. A safety factor of 3 is overweight in the aerospace industry, maybe even obese. You can check this post for conservatism in the industry: www.stressebook.com/conservatism-in-stress-engineering/
I probably have a naive question ... how do you know when to use the heel and toe concepts instead of saying that the Rht force is at the end of the bracket? If the x value increases, the force on the bolts decreases ... but then what is the right thing to do ???
The key is conservatism. You should definitely use it when the applied load is up and its a thin bracket. In other cases, Rht the way it is in this video gives you a more conservative answer, but only within reason. You need to sharpen your pencil if you have a negative margin as a result.
Thanks for the wonderful feedback. If you add two additional fasteners closer to the vertical leg on the horizontal leg, assuming they are co linear with the existing fasteners (or not), basically you are reducing the applied moment arm. At the same time you are also increasing the heel toe moment arm. The larger the heel toe moment arm the lower the heel toe reaction load will be, thereby effectively reducing overall fastener loads. The heel toe moment arm will now be 2/3rd the distance from the new inner fasteners. The previous outer fasteners can be assumed to effectively do nothing as the new pivot is about the inner fasteners.
Thanks for your prompt response. I apologize for the confusion, but i meant to say adding two holes on the vertical plate. The end result would be two holes on the horizontal plate ( like this video) and adding two holes on the vertical plate. Thanks
Good question. In that scenario, the top can be considered guided, hence the bottom will not see no heel toe. The top fasteners now will see heel toe, and the problem becomes the same as in this video (it is akin to switching loading to the reaction on the horizontal leg): th-cam.com/video/bIlnoC_Ki_o/w-d-xo.html
How would you evaluate the moment capacity around the heel? (Applied moment Px*y) I'm thinking that thinner brackets would not act as an entire section, and thus there will be a point where the upright flange would experience torque independently while the flat section stays flat. Is that right? At what force and thickness does this happen?
You are now getting into large displacements, which means you have much bigger problems now in your structure elsewhere which need to be fixed. These angle brackets are not intended for such applications. Small displacements is the key, like very small.
Excellent video!!!! It will be good as to complete this video with some calculations for the thickness of the bracket. The calculation of the thickness t as per the the actual loading strength LS = Mc *t/2 /( 1/12*b *t^3) where Mc = P*Y as per your diagram...if Allowed LS /(3*LS) -1 ...is negative...you will increase the thickness...(I'm assuming a safety factor of 3).
Thank you for your kind words. A safety factor of 3 is overweight in the aerospace industry, maybe even obese. You can check this post for conservatism in the industry: www.stressebook.com/conservatism-in-stress-engineering/
I probably have a naive question ... how do you know when to use the heel and toe concepts instead of saying that the Rht force is at the end of the bracket? If the x value increases, the force on the bolts decreases ... but then what is the right thing to do ???
The key is conservatism. You should definitely use it when the applied load is up and its a thin bracket. In other cases, Rht the way it is in this video gives you a more conservative answer, but only within reason. You need to sharpen your pencil if you have a negative margin as a result.
Thanks for providing such great videos. How would this problem chage if you add two additional holes to the horizontal plate? Thanks
Thanks for the wonderful feedback. If you add two additional fasteners closer to the vertical leg on the horizontal leg, assuming they are co linear with the existing fasteners (or not), basically you are reducing the applied moment arm.
At the same time you are also increasing the heel toe moment arm. The larger the heel toe moment arm the lower the heel toe reaction load will be, thereby effectively reducing overall fastener loads.
The heel toe moment arm will now be 2/3rd the distance from the new inner fasteners. The previous outer fasteners can be assumed to effectively do nothing as the new pivot is about the inner fasteners.
Thanks for your prompt response. I apologize for the confusion, but i meant to say adding two holes on the vertical plate. The end result would be two holes on the horizontal plate ( like this video) and adding two holes on the vertical plate. Thanks
Good question. In that scenario, the top can be considered guided, hence the bottom will not see no heel toe. The top fasteners now will see heel toe, and the problem becomes the same as in this video (it is akin to switching loading to the reaction on the horizontal leg): th-cam.com/video/bIlnoC_Ki_o/w-d-xo.html
How would you evaluate the moment capacity around the heel? (Applied moment Px*y)
I'm thinking that thinner brackets would not act as an entire section, and thus there will be a point where the upright flange would experience torque independently while the flat section stays flat.
Is that right? At what force and thickness does this happen?
You are now getting into large displacements, which means you have much bigger problems now in your structure elsewhere which need to be fixed. These angle brackets are not intended for such applications. Small displacements is the key, like very small.