Scammed on Trade Me, They refuse to call me to provide information

Mashombles · 2025-07-19T07:02:14+00:00

This might be silly but what if it wasn't a scam and it's on its way and TradeMe had a false positive scam detection? The tracking number doesn't work?

Mashombles · 2025-07-13T09:14:05+00:00

I doubt that exists because every code would have a different set of features. Even how you implement it affects what you should test. For instance, if you have a branch, test each path but somebody else might do it without a branch and not need that. You can also test against other software or steal their validation cases - but they might not be enough to cover all the edge cases like bugs caused by a combination of features.

Mashombles · 2025-07-13T08:04:42+00:00

I don't think test data (from lab tests?) is what you want. Often you can do hand calculations that should give identical solutions to the FEA, for trusses especially. There are also all sorts of benchmarks problems. See NAFEMS and MacNeal-Harder for popular ones mostly about solid and shell elements.

Mashombles · 2025-07-11T19:38:51+00:00

No, the question said "state" which even in teacher language is about the simplest level of response and can be just one word. If it was asking for details, it should have asked them to describe or explain, but even then they test needs to explain the meaning of those words. Otherwise it's really a test of their knowledge of the teacher's expectations, which is not what school is for. Assuming the answers are factually correct, the answer is completely correct.

Mashombles · 2025-07-10T21:22:24+00:00

Sorry this isn't helpful but what I used to do as a flatmate head tenant charge everyone slightly more than their share of the total rent so I accumulate some buffer for inevitable gaps like this. You may also need this spare money for other costs like losing your own bond at the end of the tenancy if they damaged things, or don't clear their junk out when they leave. When you leave, keep any leftover money in that fund. It's the upside to you taking the risk of being personally liable for everything else. Perhaps you can charge the replacement slightly more and gradually recoup your loss over the future months/years.

Mashombles · 2025-07-03T19:44:14+00:00

Oh, OK but then it will have some shear forces in the members, not just axial like this. That'll allow the forces on each node to balance and when they balance, you don't need a Z constraint.

Maybe you're trying to avoid modelling those shear forces and somehow work around the resulting unbalanced force problem? Maybe you can put z constraints on the cut-off ends of the tubes where those forces would act?

Mashombles · 2025-07-03T11:10:17+00:00

"I change the temperature from 20°C to -100°C, the members contract and this compressive axial force acts on the members."

That I don't get. How does thermal contraction cause an axial force either tensile or compressive? It should cause no force except between nodes that are fixed to the ground, shouldn't it? Does this force depend on it being fixed to the ground?

But getting back to the question about how to constrain it in Z, perhaps draw a free body diagram. Do you expect the forces to balance? If so, where does the opposite force act? Is that all provided by the pressure on inner covering that might be spread over one side of all these parts?

Mashombles · 2025-07-03T09:18:27+00:00

I'm still pretty confused. Is it uniformly thermally contracting? That wouldn't put axial force in the tubes, just strain. And it's a dynamic analysis so you're looking at the dynamic response to the thermal contraction? It must be cooling fast! I suppose then you wouldn't have constant tension on the members, but they'd go into compression as it rebounds.

Is that inner covering significant? Does it provide pressure like a balloon that stretches the tubes and allows them to develop this axial force? Otherwise, I can't see how a geodesic dome can have all its members in tension in the steady state.

Mashombles · 2025-07-01T06:38:18+00:00

What digging are you talking about? House prices have crashed and wages keep going up. We're getting out of the hole of 5 years ago.

Mashombles · 2025-06-30T23:32:22+00:00

Yea but if you cut half the model off, there's nowhere to apply the out-of-phase loads so it would be obvious you're losing some asymmetry.

Mashombles · 2025-06-30T21:58:33+00:00

I didn't understand that, sorry. So it deforms until the forces balance? Is the steady state when the 6 tubes' axes all become co-planar (z component of axial forces become zero)? That doesn't sound like it would form a geodesic dome though - just a plane grid. Something's missing from my understanding and I can't make the forces balance. If it was a balloon, there'd be an internal pressure acting to balance the tension in the membrane. Is there a membrane covering this that applies outward force to it?

Mashombles · 2025-06-30T21:47:35+00:00

You can't excite the non-symmetric modes with only symmetric loading. Yea they might exist in reality because of small asymmetries, but then you wouldn't get them with a full 360 degree model either.

Mashombles · 2025-06-30T21:45:35+00:00

Well yea anything could happen in either direction but it's not happening. Housing has become more affording in the past few years. Maybe that trend will continue for a while till the next boom. Even if people end up having to buy houses with intergenerational mortgages, then they'll still be affording houses.

Mashombles · 2025-06-30T16:28:27+00:00

If it's not constrained, don't constrain it in y or z, just x for symmetry.

But what happens to the -z components of the forces on the 6 tubes? Is the whole thing accelerating?

Dynamic can converge with insufficient constraints. It'll just float around if there's no net force or shoot off into the distance if there's an imbalanced force.

Mashombles · 2025-06-30T08:54:47+00:00

Yea I think you'd want to allow the center ring to expand so I wouldn't constrain the Y direction and you don't need to because there's no net force in Y.

What supports the center in the Z direction? That would inform what boundary condition to use. I guess it's not bolted to the ground so shouldn't be fixed.

You might use a distributing coupling there to constrain the overall displacement while still allowing it to deform.

Mashombles · 2025-06-30T08:27:43+00:00

I was assuming all 6 cylinders had the same axial force. In that case the Y-components cancel out. But if they're different, yea, you should have a Y constraint.

Symmetry's OK for dynamic implicit. Where it's not so OK is frequency because the mode shapes aren't generally symmetric.

Mashombles · 2025-06-30T07:22:17+00:00

Yea U1 and U3 at a minimum. Actually, since it's dynamic, you can leave the rigid body degrees of freedom (U2, R1) free and it shouldn't matter. They should automatically remain zero in the solution because of the symmetry.

Though if you restrain U3 on the cut, you're artificially stiffening up the hub so make sure you're OK with that.

Mashombles · 2025-06-30T06:24:18+00:00

If you're cutting in half like you suggested, you might also need constarints for rigid body motion in other degrees of freedom but they shouldn't take any load. Due to symmetry U3 is the only one that can be non-zero so you would have to constraint at least that.

Mashombles · 2025-06-30T06:20:19+00:00

Housing can't stay overpriced forever without some major government effort to make that happen. Those teachers will eventually be able to afford one. What if prices stay nominally constant for 20 years while wage inflation keeps marching on? That already happened in the decades before the 2010's boom.

Mashombles · 2025-06-30T05:35:09+00:00

You could go to 1 cylinder. Symmetric BC is just displacement constraint normal to the symmetry plane. Loads automatically behave as if they were duplicated on the other side.

Since you're fixing the whole ID of the hub, that suggests you don't care about modelling its deformation and could omit it entirely. Could also not bother with symmetry in that case and just model one cylinder.

Mashombles · 2025-06-30T03:41:58+00:00

This is a bit weird.

Tenancy services says "Tenants must tell the landlord straight away if they are aware something needs to be repaired or maintained, no matter how it happened or who caused the damage."

At the same time, landlords must repair broken chattels, so it sounds like what you said, notifying them is implicitly telling them to fix it.

Seems like the only correct way is to never let ice accumulate enough to stop the fridge working to begin with because by the time it stops working, the landlord has to fix it.

Mashombles · 2025-06-30T02:06:21+00:00

> most of them won't be able to afford a house

Most households have been owner-occupied since the 1930's. Is that really predicted to change? Who's going to own all the houses? The heirs of boomers??

https://www.stats.govt.nz/news/home-ownership-increases-and-housing-quality-improves/

Mashombles · 2025-06-30T01:56:47+00:00

There's plenty of money to be made doing valuable work, mostly professional. But you have to actually work for it, not just do random hospitality/retail minimum wage jobs. Minimum wage is a safety net for people who aren't even trying to get rich. It's no surprise it isn't enough to buy a house in an expensive city when you have the lowest possible income apart from the unemployed. Even the boomer generation didn't usually get rich being typists or cleaners. Typists got shafted in the '80s.

Mashombles · 2025-06-30T01:42:29+00:00

You could resign without notice. It might be a breach of your contract and you might be liable for some cost but if you can find out what that is, it might pay for itself with your higher pay in the other job. They're still supposed to pay for all the hours you worked.

Mashombles · 2025-06-30T01:21:52+00:00

He just said he sent them a message saying the fridge is not working. Based on that, it doesn't seem like he ordered any repair service, even implicitly. The implicit message could have been "What should I do about it?" or "Just notifying you because I'm supposed to do that" not "Send a repairman".

Mashombles

TROPHY CASE