RFEM - the effective length is not defined 2

[Pretty Girl]

Why these errors occur? This is a very basic structure to test the software. I did their steel hall tutorial as well before which it ran smoothly without any errors and at that the RFEM didn't ask to set effective lengths manually.

I just drew four legs, on top of the drew another four legs, connected those with beams and bracings and put hinged support. When I click the analyze button, it throws these errors.

Why don't it just automatically calculate the effective lengths etc. Or is it saying some other thing that I should have done?

Tension braces are also just steel beams (I just wanted to test it without wasting much time)

 

[KootK]

@milkshakelake: my volley.

But I give people the benefit of the doubt and treat them like a random human. Colorblind, genderblind, and all that. It removes a lot of assumptions and accusations. Tangentially, I also give people benefit of doubt when they don't know something seemingly trivial, because I have no idea what their life is like.

So what I'm hearing is that your are in favor of enforcing no standards / social norms here whatsoever. No minimum standards of behavior. No minimum standard of competency. No minimum expectation of reasonable growth in competency. You know, because you never know what someone else is going through, right?

I disagree. I feel that any garden worth having will ultimately wind up requiring some proactive weeding occasionally. Consider:

A) ENGISSOL. Remember that guy? The software peddler that was using our forum as a shameless advertising platform in exchange for trivial contributions? Should we have let him stay because.... what? Maybe he was having bad day/quarter? Not only would we have had to continue to put up with his abuse and exploitation of us, it would have created a horrendous precedent for the many other representatives of software companies that participate here. It would have been the path to an uglier garden.

B) R13 / ret13. You know, that dude that would contribute fifty responses to any thread, regardless of whether it was within his wheelhouse or not? Should we ask him to comeback because... what? Because was clearly a well intentioned retiree who enjoyed hanging out with us (he was)? I actually feel awful about R13's excommunication to this day. I wish that could have been resolved by way of training rather than banishment. I was one of many folks who contributed to this decision but, for me, it came down to this: I strongly suspect that the reason that JAE was absent from our lives for a spell was because of his frustrations with R13 and management not taking any action to correct the situation. And, for me, nothing uglies up this beautiful garden faster than my most significant digi-mentor being driven out of it.

Like I said, this is a probability thing for me.

If the only problem that I saw here was a handle that looked like catfishing, anti-feminism, and gonzo poor judgment, I would probably leave it alone. If phamENG decided to change his handle to PrettierGURL, for example, I would abstain from criticizing that decision because, obviously, one would have to be insane to doubt pham's intentions given the scale of his contributions here.

But the handle is not the only problem that I see here. In addition:

1) In three years, Pretty Girl has not made a single contribution to any thread other than his own. Not one: Link. Yes ,yes, perhaps Pretty Girls is just so incompetent and shy that he lacked the confidence to try and assist anyone else. Regardless, to date Pretty Girl's relation ship with this community is one sided and parasitic in nature. All take, no give.

2) I feel that Pretty Girl has established a pretty clear pattern of exploiting the good will of the folks on this forum as a substitute for investing the time required to rectify his technical deficiencies. Rather than helping Pretty Girl to improve, I get the sense that we are serving as a crutch to allow him to continue to not improve. At this point, we are enabling his incompetence.

Again, I would not normally bother myself with raising a fuss over #1 and #2 in isolation. There are plenty of members here that do the very same thing.

My willingness to call Pretty Girl out on this stems from the combination of his parasitic relationship with this forum with a handle that strongly suggests catfishing.

@milkshakelake: given the combination of a catfish-suggestive handle and #1 and #2, what would you say the likelihood is that I have indeed misread the situation here and Pretty Girl is really a transwoman employing an escape hatch?

Seriously, give me a percentage. As an engineer, you know full well that no meaningful decision is made in an environment of perfect certainty.

And at what percentage would you condone action here? Or is there no such percentage?

 

[milkshakelake]

what would you say the likelihood is that I have indeed misread the situation here and Pretty Girl is really a transwoman employing an escape hatch?

(Minor note - I didn't mean that they're deliberately employing an escape hatch. I meant that many transwomen have usernames like that, and that gives them an escape hatch from nefarious use to me because the practice is common.)

I'd say that your chance of misreading the situation is around 20%. I don't mean specifically that Pretty Girl is a transwoman; I mean that there might be more to their story than we can definitively answer here. I think the transwoman possibility is around 0.1%. I pointed out the transwoman thing because it's a possibility you may have overlooked, and there might be others. I base this on my own personal experiences. There have been times I was sure I was right, like in my relationships, when I considered all the evidence. I would run things in my mind over and over, and I was 100% correct based on my own reasoning. But occasionally, it turned out that I was missing a vital piece of the puzzle, and the other person was right.

The best way I can explain this is through a hobby of mine. I watch speedrunning. This is where valiant nerds try to beat video games as quickly as possible. There are occasionally cheaters. If they're found cheating, they get exiled from the community. But this only happens after a thorough investigation, and after definitive evidence of cheating was found. Sometimes, it's something as subtle as a score being 10 points higher than it should, or a treasure box spawning a combination of items in an order that is impossible because of the algorithm (this was a real thing in Minecraft). Anyway, the point is that the accusation of cheating isn't enough for an excommunication.

As an engineer, you know full well that no meaningful decision is made in an environment of perfect certainty.

Hard, indisputable evidence in lieu of probability should be provided for an accusation like catfishing.


Regarding A) and B) [members who have been banned]: A) has met the proof standard for the dismissal. The evidence of wrongdoing and antisocial behavior is in the posts themselves. B) is more of an opinion-based decision reached by committee, which is fine too. That's probably more in the realm of the Pretty Girl situation.

Regarding 1) and 2) [parasitic behavior of Pretty Girl]: Like you said yourself, Pretty Girl is not an isolated case. If you want to banish these types of people, that's a different discussion. I don't want to get into that, because that's a whole other issue and the train would start going off the rails. Your problem is the combination of 1), 2), and catfishing. So if the catfishing thing isn't definitive, then Pretty Girl becomes like many others. I feel like the strength of your conviction of username misuse is amplified by 1) and 2), and wouldn't have surfaced otherwise.

I think someone who can clear up the air is @Pretty Girl . I doubt they'll respond, but let's see. I'll get some popcorn ready just in case.

So what I'm hearing is that your are in favor of enforcing no standards / social norms here whatsoever.

No. I meant specifically for this case, I don't have enough evidence to say it's antisocial behavior. But I also probably have higher than average empathy, so my bar might be lower than yours. I do have a bar.

No minimum expectation of reasonable growth in competency.

I think this part of the discussion would derail this locomotive, at least for how I see the itinerary. But if you want to discuss that, we could.

 

[Pretty Girl]

Dlubal makes the RFEM software.... I'd forgotten that.

I've never used it personally, but one of my own colleagues who now lives in Philadelphia (I believe?) is their main US rep. Or, she was just a year or two ago. A friend of mine was looking for some structural software that could do something a little weird. He works on pools and does some weird curved shell geometry.

Anyway, I point him towards RFEM based on a conversation I had with my former colleague about something she had highlighted about that program. He contacted her and they provided a bunch of help. He didn't end up purchasing it at that time because the work (which was mostly side work, not his 9 to 5 job) dried up for personal reasons. But, if he jumps into a project like that again then I'm confident that he would probably start with RFEM before others.

That being said, if the OP is in Australia, I would not be surprised if the support available there is limited.

Caveat:
I worked or RISA for 16 years (which is where I met the Dlubal gal). And, I currently work for a different competitor of Dlublal. I can be considered a biased individual on all things related to Structural Engineering software. I'm a not intending to promote this software (or condemn it). Just telling relating my friends experience here in the US with Dlublal being willing to provide good support / customer service in pursuit of a sale.

Yeah, it seems to be good with unconventional shapes etc.

My major concern with most of these structural software is they don't have a mac version, so I had to use a windows laptop instead of my mac. Which I hate most of the time.

This is probably due to the limited users in mac systems who are into structural analysis and design etc. I guess almost all structural companies and individuals use windows systems.

 

[KootK]

I pointed out the transwoman thing because it's a possibility you may have overlooked, and there might be others.

Well, yeah. I intended possibility [C] to be a catchall bucket for any improbable thing that might serve as an alternate explanation. Obviously:

1) I didn't really expect [C] to be the case and;
2) I'm not going to bother attempting to list the zillions of other low probability explanations that should not dissuade us from defending our community.

C) Your recently deceased grandmother went by the nickname Pretty Girl and you chose your handle to honor her?

I think someone who can clear up the air is @Pretty Girl .

I don't support that at all.

Firstly, it would be hopelessly naïve to expect a lazy catfisher to just own up to being a lazy catfisher. So there's no functional way to gain any useful information from the exercise.

Secondly, in the unlikely case that OP really is a down trodden transvestite, I feel that is none of our business. And I feel that it would be unkind to put them in a position where they felt compelled to share such personal information. Same for any other explanation that would fall into the "highly personal" category.

Hard, indisputable evidence in lieu of probability should be provided for an accusation like catfishing.

With respect, I feel that is patently incorrect.

"Indisputable evidence" is extremely hard to come by in most practical situations. If that is to be used as the standard of proof for taking corrective action against bad actors then society simply would not have the ability to defend itself against bad actors.

Why do you think that the standard of proof in criminal courts is not "indisputable evidence" but, rather, beyond a reasonable doubt? Beyond a reasonable doubt = probability. And the bar is even lower when one considers civil court proceedings which bear more resemblance to this situation. I am, after all, not asking for OP to be incarcerated or put to death by lethal injection.

Anyway, the point is that the accusation of cheating isn't enough for an excommunication.

I haven't asked for excommunication here. I feel that a great outcome in this situation would be:

1) OP recognizes that his handle choice is clearly problematic for some of his colleagues here.

2) OP changes his handle and carries on.

Empathy, after all, is a two way street is it not?

Yes, I recognize that this might feel a bit like yielding to a bully (the bully being me). I really don't want the bully to be me though. Nobody elected me the sheriff of Eng-Tips after all. And I really do not relish the role to the extent that I occupy it. I feel that it is generally best for society to enforce its social norms collectively, by way of consensus. That's why I'm doing my best to persuade folks here, including you, that:

a) Taking some action here is appropriate.

b) The world does need more tolerance but infinite tolerance make us vulnerable to bad actors.

In future, I will simply vote with my feet and try to avoid responding to Pretty Girl's threads so long as he's using that handle. If no one else is uncomfortable with Pretty Girl's attempted manipulation of our community, they can also vote with their feet by continuing to offer assistance.

My ideal solution here is pretty much the same as what I wanted for ret13.

I wish that could have been resolved by way of training rather than banishment.

 

[Pretty Girl]

 

[KootK]

So the software already knows the effective length as it already knows the stiffness, member thickness, material it's made of etc, so inability to calculate it by it self is surprising.

It would not be surprising to anyone with even a cursory understanding of the computational method that underlies the software.

Given the tool that you are using and the problem that you are analyzing, it is highly probable that method is the Direct Stiffness Method executed under the assumption of linear elastic behavior. Folks familiar with that method will quickly recognize the following:

1) The FEM run produces analysis results, not design results. So you get moments, shears, axial loads, and deflections as outputs and that's pretty much it.

2) To the extent that the software does "design", that functionality is usually nothing more cookbook code design executed just as you would do it by hand or with a spreadsheet. Consequently, the software requires the same engineering decisions to be made that you would have to make if you were designing your members by hand or with a spreadsheet.

That said, one might wonder why the software doesn't just assume that the unbraced lengths of all of the members are equal to the physical lengths of those members? You know, do that as a default or a checkbox setting that the designer can modify if they see fit.

This is why:

I just drew four legs, on top of the drew another four legs, connected those with beams and bracings and put hinged support. When I click the analyze button, it throws these errors.

RFEM fears that their software may wind up being used by hurried, incompetent designers who expect to be able to invest five minutes worth of drafting effort and walk away with a fully functional FEM model capable of yielding actionable design results.

The software companies are attempting to protect themselves, and society, from you.

This begs the following questions:

A) Should you be using FEM software given your lack of familiarity with the method that underlies it?

B) Is it equitable that you shift the burden of understanding to the generous folks on this forum rather than sorting things out for yourself?

Many of us have strong opinions about such things but my current view is that the answers to those questions are no longer of any functional relevance. For better or worse, it is presently the case that designers unfamiliar with even the most rudimentary workings of their design software will be using such software to produce designs that society hopes will not endanger it.

Who knows may be I have thousand more years to learn or infinity.

You do not need anything like a thousand years to get this stuff sorted. If you invested 15 minutes of your lunch hours for the next six months, you could easily digest the excellent book shown below and, in the process, move yourself into the upper fifth percentile of all designers with respect to your understanding of the methods that underpin your FEM software. Surely your competence as a structural designer is worth that modest investment?

The book shown below is my favorite starter book but, if money is a problem, there is also this excellent freebie: Mastan Book.

If you are altogether too modern for books, I'm sure that someone can recommend a suitable YouTube series.

Access to information nowadays is not a meaningful barrier to anyone willing to put for the effort to understand their craft.

 

[milkshakelake]

Why do you think that the standard of proof in criminal courts is not "indisputable evidence" but, rather, beyond a reasonable doubt?

I agree; I'll revise that to "beyond a reasonable doubt." But what is that percentage in court? I'm not sure. But for me, I haven't seen the threshold crossed in this case.

I feel that it is generally best for society to enforce its social norms collectively, by way of consensus.

I agree to that as well. I'm just not seeing your case in the same way you are. The proof of standard hasn't been met for me on the catfishing. I don't know what the acceptable probability is. But I'm seeing about 20% probability that you could be wrong, which is different than your percentages. The case would be much stronger if Pretty Girl (I don't even like typing those words, but anyway...) had a provocative profile pic or said things to woo people.


I do think you're trying to bully people into seeing your viewpoint. You haven't thoroughly refuted my points, and haven't convinced me. Instead, you doubled down, so I did too. So I thought about how to break the deadlock in my mind, and found this in the forum policies:

The following activities can result in deletion of posts, deletion of threads and/or restriction of further site usage. Members who engage in any of the following activities may be flagged by the membership. Management of this site does not read any post unless it has been red flagged by a member. In no particular order, here are some common offenses:

• Leeching (members posting only questions, and never helping others)
• Irritating Other Members

After reading that, I'm on team KootK. Looks like two of Pretty Girl's behaviors have infringed upon the guidelines. So I agree with your possible remediations.

If no one else is uncomfortable with Pretty Girl's attempted manipulation of our community, they can also vote with their feet by continuing to offer assistance.

People just not responding would be a good way to fix it. That's actually what I was doing beyond one response I made a while ago, because I felt weird responding to someone with that username. When you came up in this thread though, I just had to get in on the action But I think there will be people who will respond, no matter what. See hoshang's threads. So inaction isn't really the solution. If people agree that an infringement was made, something should be done about it.

 

[KootK]

I do think you're trying to bully people into seeing your viewpoint.

I'm sorry to hear that. It's hard to know where the persuasion / bullying threshold is sometimes, especially when attempting to make use of humor.

But what is that percentage in court? I'm not sure. But for me, I haven't seen the threshold crossed in this case.

Given that all I'm asking for here is for Pretty Girl to consider a name change, I don't feel that a very high percentage is required. I would say that your 80% suspicion level is adequate. And my >95% would be far more than enough.

When you came up in this thread though, I just had to get in on the action

I'm glad that you did. I'm sure that a number of forum members feel as you do and responding to your concerns has given me, hopefully, an opportunity to respond to theirs. You have served as that contingent's champion and I celebrate that.

But I think there will be people who will respond, no matter what.

I agree. My impression is that most ET members, myself included, mostly just like the sound of their own voices. It's just so damn satisfying to have somebody else be interested in the stuff that we're passionate about.

I suspect that OP could change his handle to JEpp$teinNYC and we'd still all be falling over one another to provide the best answer to his punching shear questions...

But at least that would not be an underhanded attempt to manipulate us and insult our collective intelligences.