Any explanations why a tree would split like this?

[Tony Croft aka hamadryad]

For the monkey like forester Tony, what is the hot spot and neutral fibre zone?

 

nobody is a monkey, I was just playing with Janey cos we is like that!

 

I will draw a diagram and put it up give me a tick:thumbup1:

[RobArb]

VTA Tastic!

[RobArb]

Claus would enjoy that one:lol:

[slack ma girdle]

an extending shear bomb crack, nasty one too.

 

adding an elaboration!

 

its a shear crack, often a tree will on maturing develop a conflict of forces between the stem fibres and root plate as this alters from tap to heart rooted form. the shear bomb is a kind of stress realease but sometimes it is cataostrophic like this and continues past the neutral fiber zone.

 

You could write anything with a few big words, and most of us would be none the wiser. Keep up the good work, if in doubt BAFFLE.

[Arctostaphylos uva-ursi]

What was that.....

 

Shear bum crack?

[Tony Croft aka hamadryad]

This is an important subject and ive wanted to talk VTA and tree mechanics since ive been on AT but Im always worried about using stuff from it because technicaly im not allowed to share VTA digitaly this way, but i will see if this can be arranged as its such a great portal for sharing the subject.

 

in the meantime, heres some diagrams i hope briefly and simply explain, I will have to think about elaborating on the hot spot a bit but this explains the shear bomb and shows the hot spot/neutrel fibre zone

 

[slack ma girdle]

So why are the netural fibers hot ?

[Tony Croft aka hamadryad]

So why are the netural fibers hot ?

 

Its a "bad term" really, its called the hot spot as its the thinnest "wrist" of the stem, if a tree isnt blown out of the ground it will snap at this point, because it is the weakest part of the stem. But saying it is weak, is still over simplifying it.

 

I need to talk tensile triangles and shear squares but need to get some permision to do so, give me a long while and I will ( been meaning too) get permission to get down to a serious thread on this.

 

Janey, dont lose that photo, its a cracking example of the defect:lol:

[janey]

Janey, dont lose that photo, its a cracking example of the defect:lol:

 

I'll email them to you and your fully backed up photo account.

 

Those diagrams make a lot of sense. Have I infered correctly that you won't get shear bomb cracks in a tree that doesn't have either a lean or an inbalanced crown?

[Tony Croft aka hamadryad]

In the leaning tree shear bomb cracks often continue due to the progressive nature of the growth and wieght, not always.

 

there are other cracks in this region that can result from unusual loadings, separation shear cracks, banana cracks and hazard beam cracks can all form in the lower stem or upper root crown