Daghan Gunhan

Engineering Blog

How a structural engineer thinks.

Not tips, not tool tutorials — how a problem is framed, which method fits it, and how results are interpreted before they become decisions. Every post is built on literature, standards, benchmark studies, or real project work.

For practising engineers. The most widely read series.

Not about running analyses — about the judgement that surrounds them: design philosophy, DFMA, validation, and knowing when a simple hand calculation beats a million-DOF model.

Diagram showing the escalating cost of finding an engineering problem at each project stage

Beyond the Model

August 2, 2026

The Cost of Finding It Late

A prevented problem being invisible does not make it unimportant. A design review costs a few engineering hours; a failure in the field can cost the project.

Design ReviewCost of Engineering Decisions
Before and after DFMA redesign of a thermal sight retical assembly showing reduced part count

Beyond the Model

July 26, 2026

What If the Best Design Decision Is Deleting a Part?

A real DFMA case study: a thermal sight assembly went from 24 unique part designs to 8, and assembly time dropped by nearly 85% — while the product performed exactly the same function.

DFMADesign for Assembly
Diagram showing Strength of Materials, Elasticity Theory and FEM as layered engineering tools

Beyond the Model

June 14, 2026

Don't Get Lost in the Magic World of Big Models

Strength of Materials, Elasticity Theory, and FEM are not alternatives to each other — they are engineering tools built on top of one another. Sometimes a simple Excel sheet beats a million-DOF model.

Engineering JudgmentHand Calculations
Comparison of coordinate tolerancing and GD&T tolerance zones for four bolt holes on a mating surface

Beyond the Model

May 24, 2026

Two Parts Can Be Within Tolerance and Still Fail to Assemble

Traditional coordinate tolerancing controls dimensions, but not always function. GD&T defines behavior — and in engineering, functional behavior is what truly matters.

GD&TTolerancing
Analysis of a thermoplastic flange connection with steel bolts and elastomer seal under cryogenic temperature drop

Beyond the Model

May 17, 2026

Extreme Environments: Cryogenic and Vacuum Systems

A design that works perfectly at room temperature may fail completely in a cryogenic environment. In extreme environments, small details can become very big problems.

Extreme EnvironmentsThermal Effects
Diagram illustrating the principle of adding model complexity one step at a time

Beyond the Model

May 3, 2026

Add New Things to Your Model One at a Time

Whether you're new to analysis or expanding your capabilities, the biggest mistake is adding multiple tools and features at once, then asking why the result looks the way it does.

Modeling StrategyNonlinear Analysis
Two shear force and bending moment diagrams for the same system and load, showing how different boundary conditions change the critical region

Beyond the Model

April 19, 2026

A Large Portion of Your Results Comes From Boundary Conditions

No matter how detailed your model is, incorrectly defined boundary conditions can lead you to completely wrong results — even the critical region can change.

Boundary ConditionsEngineering Judgment