Ash tree core cracks ?

Clarification - even injected and producing foliage, the quantity of sap from the still present partial damage is likely reduced and thus the potential for lessened moisture content in the wood. Injections still leave bugs, they just hinder them from being fully high-capacity destructive. And there's the chance of less than ideal batch of Treeazin or whatever for the injections. Imidacloprid is only 70% effective but sustained my trees for several years. Cut with a diminished but viable foliage state. I didn't get to see the trunk wood because a city crew inhaled it into a chipper. Would have been interesting.
 
Sean, dig around and find the nerd content about trunk stress in bending. The wood should fail because the shear strength was exceeded and usually some sort of stress riser/focuser causes the exceeding circumstance i.e. changing the support cross section during the act of cutting. Wherever/whatever the post I believe there might have been diagrams etc.
 
Check to see if these cracks are occurring in the neutral plane. Like others have said alder and maple do this as a norm, sometimes violently! I’ve felt a pop after the piece has left the spar, to see a 1/2-3/4 crack that has opened up.
Even bucking wood on the ground post removal and hanging out around lunch can sound like a muted popcorn popper just starting to take off.
Besides internal stress of reaction wood, the other factors are: difference in moisture content from heart wood to soft wood. And quite possibly pressure changes in the wood from compression and or negative pressure in water columns being released likely causing a short term radical drying in the wood
 
We need the nerd diagrams showing compressive and tensile regions of a beam in bending, and then the vertical version where gravity kicks in a little extra compression. There was a video I recall. It might have been in a Daniel thread attempting to enlighten.?

It's not the shear plane, you're thinking of the neutral axis where the shear is zero.
 
GregManning said:
Still not clear. ;)

References ?
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hmmm, ok will try to do my best. Try to straighten out a banana. When you do so the inside of the curve is under tension, and the outside of the curve is under compression. The inside curve fibers are being stretched and want to rupture, the fibers on the outside of the curve are getting squished or buckling.

Think of this in a diagram cross section with arrows of force, near the middle plane you have a zone with arrows going in opposite directions. This is the neutral plane or shear plane, and cracks in this plane will propagate outwards to the sides.

Now take this in wood, trees will put on adaptive growth.. Most conifers add compression wood to straighten out themselves, most others add tension wood. So the wood fiber is like a coiled spring, or like a strong cable. Cut off all the limbs, and start releasing these forces in the trunk. You have removed all loading the tree grew to adapt to, the banana is straighten it's self, like a big back bend stretch after slouching on the couch.. I know I pop when I do this!

Trees will put on adaptive growth for about anything.. Prevailing winds, shade, torsional loading, and just gravity! It's when these outside forces suddenly change, like the storm of the decade coming from the opposite direction of the prevailing winds! I typically say something along the lines of "Our prevailing winds come from the south to the west, and our storm of the decade comes from the north. I see a little damage with a 70mph windstorm from the south, but I see 3-4 times the damage from a 50mph windstorm from the north.

A bit of a ramble, hope this clears it up
 
evo said:
hmmm, ok will try to do my best. Try to straighten out a banana. When you do so the inside of the curve is under tension, and the outside of the curve is under compression. The inside curve fibers are being stretched and want to rupture, the fibers on the outside of the curve are getting squished or buckling.

Think of this in a diagram cross section with arrows of force, near the middle plane you have a zone with arrows going in opposite directions. This is the neutral plane or shear plane, and cracks in this plane will propagate outwards to the sides.

Now take this in wood, trees will put on adaptive growth.. Most conifers add compression wood to straighten out themselves, most others add tension wood. So the wood fiber is like a coiled spring, or like a strong cable. Cut off all the limbs, and start releasing these forces in the trunk. You have removed all loading the tree grew to adapt to, the banana is straighten it's self, like a big back bend stretch after slouching on the couch.. I know I pop when I do this!

Trees will put on adaptive growth for about anything.. Prevailing winds, shade, torsional loading, and just gravity! It's when these outside forces suddenly change, like the storm of the decade coming from the opposite direction of the prevailing winds! I typically say something along the lines of "Our prevailing winds come from the south to the west, and our storm of the decade comes from the north. I see a little damage with a 70mph windstorm from the south, but I see 3-4 times the damage from a 50mph windstorm from the north.

A bit of a ramble, hope this clears it up
Click to expand...
Outstanding ! :)
 
As for the cracks, how about from the mechanical stress from felling? Bash and crash and all that. I've seen that happen in beech and maple of size. Sure, may well have been "pre-loaded" with stress. Some rips might explain it, maybe not.
 
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