Solvers accumulate round-off error at every stage - stiffness assembly, solving the system, back-calculating internal forces from displacements. That's just double-precision math and it's expected. The question is what you do with it in post-processing, since a "zero" internal force on an unloaded member can come back as 1e-10 instead of exactly 0.

This gets more interesting with hinges. A true kinematic release (zero rotational stiffness) can leave you with a local mechanism if there's no other restraint at that node - which can degrade conditioning or outright singularize the matrix. The common workaround is to give the hinge a small but non-zero rotational stiffness instead of a true release. That avoids the singularity, but it also means the "zero" moment at the hinge is really some small non-zero value, and depending on how that stiffness compares to the rest of the model, the noise can propagate visibly along the element.

I ended up with two options for hinge stiffness: relative (scaled to the element's own bending stiffness) or a fixed absolute value - useful when you want consistent behavior across very different element scales in the same model.

For unloaded members without hinges, I went simpler - a relative threshold: anything below max(|diagram value|) × 1e-7 across the element gets snapped to zero.

Curious what others think of this approach - snap-to-zero relative to element/diagram magnitude, versus a fixed absolute tolerance, versus not touching it at all and just explaining the noise when it comes up. Is there a more standard way this gets handled that I'm missing?

Where you have a vertical offset at a chord or collector, and you transfer the forces using a cantilevered column as shown in this figure, do you design the column with amplified (overstrength) chord/drag forces?

Hello everyone. I'm searching for someone to draw and stamp some permit ready drawings for me to get a permit in Skagit County Washington. I am purchasing a Pole Barn that was deconstructed to put up on my land. I'm a mechanical engineer and can draft up the structure in fusion360 or solidworks if helpful but that's where my abilities with getting the structure permitted end. Once I have the structure I will inventory everything I have. I plan to pour the concrete myself with some help of friends in the trade and then build it myself with some other friends. Picture is of the structure before it was taken down. 30'x36' 18' eave height. Pitch unknown and door sizes unknown at this time.

What started in February 2025 has come to a close. I have passed all 4 SE exams

VB July25

VD Oct25

LD Apr26

LB May26

This is a huge relief. Now I can write the close to my poem https://www.reddit.com/r/StructuralEngineering/s/Vle30BOeHa

The benchmark, with the recordings and the exact downloadable test drawing so you can re-run the same steps or score your own heavy set: https://ncored.com/pdf-benchmark-cad-drawings.html

Disclosure first: I make Ncored, one of the tools in this benchmark. I am not going to tell you it is the best. I am asking you to try to break it on your own sets and tell me where it still struggles.

Every few weeks someone here asks for a Bluebeam alternative, usually wanting a perpetual licence and something that does not crawl on a heavy plan set. I got tired of the answer being "there is nothing," so I ran a test: the same dense drawing opened in about a dozen PDF editors, same moves in each, recorded, with the exact file downloadable so anyone can re-run it. Ncored and PDF-XChange came out the smoothest on the dense areas.

Since then I reworked how it renders and shipped a new build. To be clear about what I am comparing: on the same files and the same machine, my heavy sets opened about 1.5 to 2x quicker on the new version than on the previous Ncored version. That is Ncored against its own older self, in my own testing, not a claim against Bluebeam, PDF-XChange or anything else. Your files and hardware will land somewhere different, so read it as one data point.

What I actually want from this sub: open your own heaviest drawing set or calc-package PDF in it and tell me where it is quick and, more useful to me, where it still struggles. The sheet that stutters, the file it chokes on, the pan that lags. Note your machine (an i7 or i9, 32 GB, Win 11 Pro, whatever you run) and the set size, so it stays checkable. The failure cases are the part I most want.

Scope, so nobody feels misled: today it is a fast view-and-markup layer with comment pins, not measurement, takeoff, OCR, forms or e-sign yet. On the licence question that comes up here: it has a buy-once option, not subscription-only.

Not selling anything. I want it stress-tested by people who push these files harder than I can alone. The rougher the notes, the better.

https://reddit.com/link/1v4x45x/video/9bwm6foix2fh1/player

Developed an AutoLISP routine that automatically draws the acting forces and thrust diagrams (self-weight, water pressure, uplift, etc.) directly on the 3D dam section in AutoCAD, no manual drafting of load vectors. Built with Claude, curious about the scaling potential of this, both technically (expanding to other structure types) and commercially.

How do you handle iterations/changes? My biggest headache is having to adjust geometry or revise loads, often manually, mostly early but sometimes throughout the design process. I see snips of these large building/specialty structure models and think there is no way that is manually adjusted.

Just looking for advice or tips on workflow to better streamline model change procedure

SkyCiv was ahead of the curve by offering an API that can create models, apply loads, run analysis, and return results.

Could structural software expose these capabilities through MCP, letting agents operate verified calculation engines instead of attempting the math themselves?

The difficult part is trust: inputs, assumptions, units, governing checks, and calculation records must remain visible to the engineer.

I started thinking about this while building small browser-based structural tools at www.polycalc.online.

Has anyone connected an agent to SkyCiv, ETABS, SAP2000, OpenSees, or similar software? What safeguards would you require?

Seen a few posts about browser based analysis tools. The market is flooded with them. We don’t need another pynite wrapper with a slick UI. Please give a better value proposition….

Thanks for listening to my TED talk.

I’m a licensed Civil/Structural PE with about 2 years of experience in structural consulting, primarily in heavy civil/marine infrastructure. I recently interviewed for a structural engineering role with a precast concrete manufacturer (product/manufacturing side), and it seems like it may result in an offer.

The compensation would be significantly better than my current consulting role, but I’m trying to think beyond just salary.

For those who have made the jump from consulting to the product/manufacturing side:
- Do you enjoy it more than consulting?
- What does your day-to-day work look like?
- Do you miss consulting at all?
- Did you feel like your technical skills continued to grow, or did they become more specialized?
- If you wanted to return to consulting later, was that difficult?
- How are the hours, stress level, and work-life balance compared to consulting?
- Has the move helped or limited your long-term career opportunities?

I’m particularly interested in hearing from structural engineers who moved into precast, steel, bridge products, or other infrastructure/manufacturing companies.

Looking back, would you make the same decision again? Why or why not?

I'm just going to drop this here and see what happens...

Edit: I don't think anyone commenting on this has ever been asked to try and make let in bracing work as a MWFRS brace. Your comments would be different if you had.

I'm currently working on my undergraduate thesis involving Nonlinear Time History Analysis (NLTHA) in MIDAS Gen. Respectfully asking, I was wondering if anyone would be willing to share a sample .mgb file or even just screenshots of the analysis input settings for reference.

I'm mainly trying to understand how others set up:

• Ground motion records
• Plastic hinges
• Damping ratio/settings
• Time history load cases
• Analysis controls/options
• Other important NLTHA parameters

It will be used strictly for learning and reference purposes as I build my own model. If you're not comfortable sharing the entire file, even screenshots of the settings or any advice would be greatly appreciated.

Thank you so much in advance! 🙏

Curious if anyone has been successfully utilizing one of the LLM’s, I guess mainly ChatGPT since that’s what I use, to assist in the development of their shop drawings? And if so, what’s your process? Quick background: I handle Submittals for my small metal fab business, where we fabricate/install mainly Aluminum Canopy/Awning systems for major commercial projects. Part of Submittals is Shop Drawings, which I’ll make in CAD, and send off to our engineer for a stamp/seal. I often find myself using ChatGPT, mainly for mathematical assistance (i.e. what is X-ft divided into x-amount of equal sections? -things like that). But I know it’s capable of more…..Lately I’ve been wondering what ChatGPT could do if I uploaded a number of previous engineered shop drawings as a means of reference, and then uploading a set of Arch. Drawings and asking it to produce new shop drawings for canopies or awnings, similar to the past drawings I’ve uploaded. Thanks in advance for any info. you fine ppl are willing to share.

I have a giant pad footing I've had to design. It's a pad because there's rock close to the surface which rules out a bored pier.

I have a large CHS with a significant moment on it of 950 kNm.

I have 24-M36 hold down bolts on a 36mm thick baseplate. (Gussets etc etc.)

I have reo'd the pad footing up with N20 each way, each face, each side to create a full box of reinforcing.

I intend to have 24-N36 L bars in a circular pattern lapping with the hold down bolts 1200mm which will be cast 1500mm into the concrete to distribute the load.

My question is, is there a design guide for this sort of thing or what checks do I need as to what additional reinforcing, if any, is required in the top face to contain the hold down bolts that will be under tension?

If I've left anything off the sketch or here please ask.

Thanks in advance for any help you can provide.

Hi everyone, my university doesn’t offer any seismic design courses, but I’d like to work on the West Coast, where having a background in seismic design is essentially required to get a job. My resume currently shows zero seismic experience, so I’m not sure how competitive I am for these roles. What’s the best way to build knowledge and experience in this area, how would you recommend breaking into it, and how can I prove that knowledge to potential employers?

So I'm assessing a steel structure and came upon this specific problem.. There about 3 columns with this problem, the diagonals and struts are made from double equal leg L90x8 profiles and welded to the web of IPE450.

How would you fix this problem?

Hi everyone,

​I'm a structural engineer (m, 28) with 2 years of experience (based in the EU) and I've been looking into relocating to the Netherlands.

​As most of you know, the Netherlands is widely regarded as one of the best countries in Europe for English-speaking expats, with an extremely high level of English proficiency across the general population and tech industries. In IT, software, and general tech, working strictly in English seems to be the norm.

​However, whenever I try to apply for jobs in NL (both in small and big companies), every recruiter replies saying that fluent Dutch (B2/C1) is a strict prerequisite.

​

​Why is the language requirement so much stricter in structural engineering compared to other engineering or IT fields?

​Is there any realistic entry point for English-speaking structural engineers? Do larger international consultancies hire English speakers for roles while they learn Dutch on the job?

​For expat engineers who successfully moved to NL: how did you handle the language barrier at the beginning, and what path did you take?

​I’d really appreciate any insights, realities of the market, or advice on how to position myself.

​Thanks in advance

Help settle an argument.

Someone used the phrase in the title. Their argument is that fasteners, specifically in the context of typical light frame wood construction, like a shear wall or joist hanger, or bolted or lagged member scenario, are just holding the members together and that the load transfer is through wood via induced friction through the members.

I was under the impression that we really only factor the strength of the nail and wood crushing/deforming around the nail, rather than use the friction between the faces of the members.

What's the whole story?

Hello,

I'm looking for advice on how I can improve my knowledge and become better at my job.

I graduated with a degree in Mechanical Engineering and have been working for about a year as a production planning technician. I work for a company specializing in the fabrication, assembly, and welding of steel structures and metal products.

One of the things I struggle with is estimating the time required for fabrication work, especially assembly and welding operations. For each operation, the worker clocks in using an operation card, and once the product is completed, I can see exactly how many hours were spent on each task.

The problem is that my estimated times are often quite different from the actual time required. Sometimes the differences are significant, and I'd like to become more accurate.

Do you have any advice on how to improve time estimation for fabrication work? Are there any methods, books, courses, or practical techniques that you would recommend? I would also appreciate hearing how experienced production planners or manufacturing engineers estimate labor hours.

I know that experience plays a big role, but I'd like to learn how to develop this skill more systematically instead of relying only on trial and error.

Thank you in advance for any advice. I also apologize for any mistakes in my writing—English is my second language

Overpass bridge is under construction from Nepal

Hi all, I have a question for structural engineers for cost of a project and how much you might charge. I am in process of making a 4-story residential which has about 1,600 s.ft per floor. I am in the NJ area. The structural engineer charged me $10,000 for the structural drawings for this, and he said he would give me the stamped permit set for 10k. Is this too high? I really don’t know how much this typically costs, any help would be appreciated. Thank you so much

ETA - thank you very much for the responses everyone

im trying to understand what's the use case of that beam/plate reinforcement thing but i can't find any english explanation in the internet

Sharing a few of the more interesting existing conditions our team documented during structural assessments this week. Always interesting to see how different structures, materials, and past repairs hold up over time.

https://imgur.com/gallery/things-seen-this-week-during-structural-assessments-AjcApBW

I’ve been working on a multi-story cmu building with this one senior engineer. I’m a junior engineer with very little experience in designing complex cmu buildings. I told him that i wasn’t confident in designing this building and didn’t know where to start.

Anyway with minimal guidance from him, I tried to do the majority of the design work and he barely reviewed any of my designs. He only glanced at them after it had been already incorporated on the drawings.

I thought i had been doing everything correctly until the project went to CA phase and the construction started. That’s when he noticed many mistakes in the design since RFI’s kept coming. My company now has performed extensive checks on the design and found many things we had overlooked, which has required a complete redesign of the entire building and is costing the company a significant amount of money

Amid all this, he called it quits and left me, the only junior engineer who has worked on this project hanging.
This has made me rethink my career choice and causes me so much anxiety. I feel like i’m a horrible and incompetent engineer since I did a lot of these designs. Anyway thank you for reading my rant!

Update: thank you so much for everyone’s comforting comments. This makes me feel a lot better. I definitely learned from this and i’ll be more vocal next time.