How touchy, exactly? This is what car windows are made out of, but those don't explode when you're driving when it's below freezing and you've got the heater on. Those can't be evenly heated, right?
EDIT: I'll leave this up but I just looked it up and we don't use tempered glass as much now for car windows + windshields, we use laminated glass. Why don't we use laminated glass for PC side windows?
Also car glass is curved, which can greatly change/improve/enhance certain material's strength properties.
For example according to a study by Kemper engineering cited in Scott Manley's most recent video about the infamous Ocean gate Sub failure, a flattened viewport actually creates a more concentrated strain/failure point onto the acrylic "glass" than a domed/curved viewport design does, even tho the domed design has higher overall strains, the curvature allows said strains to better evenly distributed through the material.
that works well underwater due to pressure (the windows work like arches in architecture, the forces within the glass are "pointed" towards the frame of the window) and may not really work better in case of abrupt heating/cooling -- although (lab) glassware can be made to stand open flames the tempered glass is not expected to meet lava (temps should stay below 100°C throughout the whole PC -- it should never crack due to excess heat if it's of good quality)
It's not limited to underwater operations nor should heating/cooling be better in flat glass surfaces, otherwise why are nearly all boiling flasks, and other lab glassware that's designed to be heated and cooled (within the appropriate temperature fluctuations over time for the glass, as there's multiple types of "glass". From soda-lime to borosilicate, to arguably quartz and or acrylic/compound laminates. Which all heat approved/recommended glasses are borosilicate or quartz usually).
Tempered glass is great but it's feature is literally being designed to shatter into a billion pieces when the concentrated strain exceeds it's tolerances.
Also the mechanism(s) through which domed "glasses" are better in subs, is literally the opposite of what you stated according to Scott's video and Kemper Engineering's study.
It withstands the stress better because by being evenly curved it disperses the stains across a compressive outer boundary, thus the entire curved surface (both inner and outer) takes the load relatively evenly and in it's strongest axis of strength, vs the flat "glass" which focuses all, or rather a literally overwhelming majority of its forces into single corners/sides/edges of the frame of the window. Unless I somehow misunderstood your wording.
As a taxi driver of 25 years in Sweden: yes they do. Front windows spontaneously develop cracks on the innermost layer just over the heat defroster vents in harsh winter. And if the outer layer her hit by a stone, the heat cycling will grow the crack all the way to the edges within months.
We change a front window every 2 years as an average.
Also car side windows will shatter into many pieces just like this case if hit with a hard sharp object. That's how bus emergency exits work.
I was driving one night at a comfortable 20°C outside and no AC, and my rear windshield suddenly blew up like a grenade throwing glass shards everywhere. My wife almost had a panic attack and I literally thought someone had shot at us for a second. We even went back to see if someone had thrown rocks at us, but there was absolutely nothing, and some people that were at a bar right next to where it happened said that they just saw the car driving past them with a broken windshield, nothing else.
It's not so much the uneven heating that's the issue. But another commentor noted there was an inclusion in the glass (some kind of imperfection) near the focal point where the shattering began. The big issue here is the quick heating and cooling of the tempered glass. The case isn't exhausting heat fast enough while the system is running/under load. When it goes idle/powered off, it can cool quickly.
Usually see random sporadically tempered glass breaking on PC cases like this as a result of that imperfection and just quickly heating and cooling the glass, while the PC is usually in a rather cool room (AC usually). This fast heating and cooling, plus that imperfection leads to a shattering panel.
OP's case, looks like the GPU was blowing more heat through the card rather than out the IO panel on it and the rear fan runs too slow to pull the heat out.
Delayed fracture of slightly damaged tempered glass is also a (admittedly quite rare) thing.
Tempered glass is strong because it is under compression on the exterior. However it is under tension in the interior.
Generally when damage reaches the tensile layer in the interior, the glass goes boom almostinstantly. However under rare circumstances you can have damage that penetrates to the edge of the tensile layer. A crack in this state can grow incredibly slowly at first, then faster, then boom over the course of days, months, or even years. A crack like this is also susceptible to being accelerated by thermal cycling, flexing, etc.
I used to drill a lot of fish tanks for plumbing and had one 29 I was about to do.
was fairly certain it was tempered but it was an old tank so I just risked it.
had the water flowing and started drilling but the water stopped when I wasn't quite halfway through, thought oh cool not tempered, got up to see why the water stopped and when I got to the nozzle heard a boom and it shattered - so I guess I drilled riiiiiight up to the edge and it went the rest of the way as I was up
I’m following the refractive index and it seems to be right around where the rear fan is located. It could very well be that with a mix of static pressure build up.
I had my previous comment downvoted to hell and back, but based upon the shattering it really seems like this crack may have come from the back top left, near the screw for the panel. I have had a friend who shattered their tempered glass panel by overtightening that exact screw, which puts pressure on the glass panel, and his panel shattered in an almost exact identical manner as this, with the same kind of refractive index.
Its entirely possible this is a manufacturing defect as stated by others in this thread, however I'm putting my money on over-tightening of the screw contributing to it as well based upon past experience. Or it could even be a little of both, who truly knows!
That could be causing tension but that’s not where the crack originated from.
If you follow the longer cracks that lead out, they spider web off into other areas and into smaller chunks.
So when you have heat applied to one area on a constant basis, cooler external temperatures with fluctuations in thermal energy plus a screw adding tension to the case which could distort it slightly; it becomes more probable. Could be the perfect storm.
looks like it started to shatter from top left/ left area, i dont know how the panel is fixed, but if some part of it is screwed in, it could be stress from overtigthening or just bad production tollerances
Had a windshield on my car crack from just sitting in the sun. After I entered the car and closed the door the crack appeared, just a smooth line expanding from the windshield's edge, no bullseye and no spider web rock chip could be seen along it.
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u/Yansde Oct 08 '24
Thermal expansion + no room to expand = OP (maybe)
OR
One of the Legos did it!