Truss Calculators

Started by Medeek, March 12, 2013, 06:33:08 AM

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0 Members and 6 Guests are viewing this topic.

Don_P

I start coming undone with group action, eccentricity of the bolted plate connection and splitting. Do keep fabrication as simple as possible. I could forsee sawing plates with an abrasive blade onsite. Plywood connected lightweight trusses are another.

I hope the surgery goes well and brings relief, keep us posted on how you're doing.


Medeek

Yes, the big day is today.  Surgery at 10:00AM in Olympia (Olympia Orthopedics), replacing the C6-C7 disk with an artificial disk.  A little nervous about the whole thing, this being my first major surgery or procedure.  The Doctor who is doing my surgery has done almost a hundred of these and fusions though so I'm pretty comfortable he should get it right.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer


Medeek

Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Don_P

Wow, you're already upright! Good deal. I know that disc. Hoping for a speedy recovery.

Adam Roby

I had lower discs done summer before last, and I was in no condition to be posting stuff on any forum - you should really rest. 
Took me about 7 weeks before I could really walk right, was a slow process.  Hardest for me were the meds, I am super sensitive to any pain killers so I couldn't really take them, but then the pain would be too intense... it was a delicate balance of cutting the pills in 4 and dosing myself as I saw fit. 

Hope you have a speedy recovery. 


Medeek

I've got a neck brace on so its pretty much immobilzed, but  your right I'm going to take a break for about a week and lay low.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

MountainDon

Take it easy and do follow the doctors' instructions; do's and don'ts
Just because something has been done and has not failed, doesn't mean it is good design.

azgreg


Medeek

#508
Version 1.7.2 - 12.16.2016
- Enabled custom layers for roof returns, battens and counter battens.
- License renewal enabled in Medeek Account Manager.

Feeling much better today, even though it still hurts to swallow.  Back at it, programming is just too addictive to leave for too long.  I'm not too worried about over doing it since the neck brace keeps me from any movement, I just can't do things that require me to twist my neck around like driving or any sort of sports etc...

I like the new addition of the layers, it helps being able to hide certain aspects of the model.  This has led me to think it might be useful to somehow implement materials (colors, textures), either at the layer level or based on the geometry (ie. specific color or texture for the I-joist web -> OSB wood).

Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer


Medeek

Version 1.7.3 - 12.17.2016
- Added a "Materials" tab within the global settings; Auto material assigment (colors and textures) is now an option.
- Enabled materials and custom layers for floor trusses and joists.
- Enabled materials for common trusses: metal plate connectors, lumber, and OSB.





By default the metal plate connectors, custom layers and auto materials is turned off in the global settings.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

#510
- Enabled metal plate connectors for floor trusses.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=ec5402ad-0916-46f7-a84d-1bf7e57ed30f
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Looking through some old plans I've managed to dig up I came upon a couple of designs by another engineering firm. 

Typically when I've dealt with truss designs I always seen a scarf cut on the bottom chord with the top chord remaining un-notched.  In this other example the bottom chord is kept intact and the top chord is scarf cut or notched, while still allowing a continuous section to extend for the overhang with a depth equal to at least 1/2 the top chord depth.  I think the picture below explains this far better than I can with words:



For MPC trusses I am used to seeing a 1/4" butt cut, however for timber trusses what is more appropriate?

Which method above would go with (arch. and structural reasons)?

View model here:

https://3dwarehouse.sketchup.com/model.html?id=6d3633a4-3b5c-4b9f-9780-23be5230c66d
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Plates applied to the top truss:



Specs:

- Truss Type: King Post
- 6x10 TC, 6x8 BC, 6x6 kingpost
- Plate thickness = 0.25"
- single row of bolts with two bolts per row.
- connector plate width = 4.0"
- Bolt Dia. 3/4"
- Bolt Edge Distance (timber) = 4.0"
- Bolt Edge Distance (plate) = 2.0"
- Bolt Spacing = 4.0"
- Bolts and Washers not shown. 

View model here:

https://3dwarehouse.sketchup.com/model.html?id=ed8f688c-a1a2-4c2a-b09a-8ee937060922
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Don_P

#513
Top model right heel is how I do it in timberframe.






Medeek

What do you call that little wedge shaped cut?
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Don_P

#515
I still call it a birdsmouth. It's face is sized for end grain compression x Hankinson, I tried to bisect the angle. To the right there needs to be enough shear area. There is allthread and big washers across this joint, your plate does that. The bird is absorbing the rotation in the plate that looks like it wants to induce splitting in the bolt rows.
This is another way I played with it


Here's another example of that birdsmouth method from above



Don_P

OT but I remembered this crosspipe joint, I mocked it up after reading a research paper. It's supposed to be an easier heeljoint thrust restraint. I didn't really think it was any faster or better but more grist for the mill;



Medeek

This particular joint on a gambrel attic roof I am finding particularly difficult to plate:



Luckily I have a few samples to use as guides.  Given my web configurations at this joint this seems to be the most reasonable method to plate this joint.  Note that the plate  should touch the interior corner and the exterior of the lower top chord but at the same time not project past the lumber into the spaces.  Also the plate is rotated so that it is parallel to the upper top chords pitch.

The algorithm I devised to do this is quite clever I think but can be boiled down to a few concise lines of code:

        # Plate 2 (Gambrel Left)

x2 = @W2x2 - (mpcyy)/(sin(@Phi2))
y2 = @W2y2
m2 = tan(@Phi2)

x1 = @X2
y1 = @Y2
m1 = tan(@Phi1)

x0 = (y2 - y1 - m2*x2 + m1*x1)/(m1 - m2)
y0 = y1 + m1*(x0 - x1)

xoffset = (mpcxx/2.0)*(cos(@Phi2)) + (mpcyy/2.0)*(sin(@Phi2))
yoffset = (mpcxx/2.0)*(sin(@Phi2)) - (mpcyy/2.0)*(cos(@Phi2))

mpcx = x0 + xoffset
mpcy = y0 + yoffset
mpcrot = -@Phi2
MedeekMethods.metal_plate mpcx, mpcy, mpcxx, mpcyy, mpcrot, "PLGL"


# Plate 2 (Gambrel Right)

mpcx = @X5 - mpcx
mpcy = mpcy
mpcrot = @Phi2
MedeekMethods.metal_plate mpcx, mpcy, mpcxx, mpcyy, mpcrot, "PLGR"


This joint has been the most difficult so far, everything else has been cake.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Version 1.7.4 - 12.20.2016
- Enabled metal plate connectors for gambrel attic trusses.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=5297dc32-fe7a-4bdc-bab2-ccadba5e5147
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Version 1.7.5 - 12.24.2016
- Enabled metal plate connectors for valley truss sets.
- Enabled materials and custom layers for valley truss sets.



Merry Christmas to all.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer


Medeek

Version 1.7.6 - 12.26.2016
- Enabled metal plate connectors for monopitch trusses.
- Enabled materials and custom layers for monopitch trusses.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=40819b39-458c-4e87-8a5e-fe16982dfe1d
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Version 1.7.7 - 12.31.2016
- Enabled materials and custom layers for gable, hip, shed, TJI and dutch gable rafter roofs.

Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Version 1.7.8 - 01.02.2017
- Enabled materials and custom layers for gable dormers.
- Added advanced options for gable dormers, enabled exterior wall sheathing option.



View model here:

https://3dwarehouse.sketchup.com/model.html?id=5b255dad-4823-450d-a7d9-153d983e73a5
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

This is an example of custom layers and materials implemented in the Medeek Truss Plugin and Medeek Foundation Plugin and used in one model:



View model here:

https://3dwarehouse.sketchup.com/model.html?id=5ff9d1dc-7384-4c7f-bc8a-915c2cd3fc6c

Turn off the sheathing layers first to reveal all of the structural framing etc...

Regular walls were created with the Housebuilder plugin.

The trim tool in the Truss Plugin was used quite successfully to manually trim back the dormer roof framing and sheathing.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer

Medeek

Spent some time this morning traversing through the common truss code updating some of the truss types so that I can enable energy/raised heels for all common trusses as well as enable custom layers, materials and connector plates. 

As I've developed the plugin and added new features I used the fink truss as the cutting edge, so everything having to do with this truss type is pretty much up-to-date, however some of the other truss types are seriously lagging so a little house cleaning is in order.

It may be a few days before I can release this latest version since there is a lot of tedious work ahead.
Nathaniel P. Wilkerson, P.E.
Designer, Programmer and Engineer