This article explores the decline in structural behaviour knowledge among engineers and the importance of revitalizing this essential skill.
In structural engineering, the “feel” for how structures behave under various forces is more than a skill—it is the cornerstone of competent design. This is a skill that is critical to the very make up of a competent engineer. However, with the rise of computational tools, this intuitive grasp of structural behaviour is diminishing. Engineers today often rely heavily on software, sometimes at the expense of critical thinking and foundational knowledge.
This article explores the consequences of this shift and offers practical steps to rekindle the engineer’s “feel.” for the structures they design.
A Defining Moment
One day during my internship with a construction firm, I was preparing bar bending schedules for the third-floor stage for a proposed development when one of my most significant mentors walked into the site. Usually, his visits meant a thorough tour of the project, detailed observations, and engaging discussions about arising issues. However, on this particular day, he made an unusual request: to review the drawings instead of touring the site. While studying the drawings, he suddenly asked, “When are you doing the staircase?”
I explained that the contractor’s policy was to delay the construction of staircases until after the deck, though unaware of the real reason. Unknown to me, there was a fundamental issue with the design. The architect had specified a straight-flight staircase spanning 7.5m without intermediate support, while the structural engineer had designed it as a conventional staircase with a waist thickness of 175mm. This oversight, which violated basic structural behaviour principles, required a redesign with an embedded stringer beam.
At the time, I could not fully comprehend the gravity of this issue. My mentor’s frustration over the phone with the engineer responsible, however, made it clear that fundamental principles of structural behaviour had been neglected. This experience remains one of the most defining lessons of my career and a glaring example of the growing disconnect between structural design and the engineer’s intuitive “feel” for structural behavior.
The Engineer’s “Feel” for Structures
An engineer’s “feel” for structures refers to their intuitive grasp of how a structure responds to various forces and loads. This understanding allows them to assess the feasibility of design decisions without any reliance on computational tools. It is not about memorizing rules but developing an instinctive sense of what works and what does not.
My mentor often stressed, “You’re not yet a competent engineer until you can have a feel of the structure you’re designing.” Practically speaking you should be able to see where the load goes to, and you should be able to predict how a structural member is going to react under load without putting a pen to paper.
This concept is indispensable. Engineers with this skill can spot design errors at a glance, optimize solutions, and ensure the structural integrity of their projects. For example, preliminary sizing rules should have immediately flagged the inadequacy of a 175mm-thick staircase waist spanning 7.5m. Yet, in many cases today, such errors go unnoticed until construction or peer reviews.
The Growing Disconnect
The shift from hand calculations to software-driven design in the 1990s brought unparalleled efficiency but inadvertently widened the gap between engineers and their understanding of structural behavior. Many professionals now rely heavily on software, treating it as an infallible authority. Unfortunately, this dependency often blinds them to critical design flaws.
Peer reviews of structural designs frequently expose this gap. Over the last six months I have conducted several peer reviews on proposed high-rise buildings. As I write this article, I am still disgusted by some of the design decisions I have had to review. Perhaps, this disgust reached a peak, during a review of a proposed 20-story building, I encountered transition beams sized at just 230 mm x 600 mm to support loads from as much as 20 floors. There’s no doubt that basic structural intuition should have flagged this as grossly inadequate, should this drawing have been prepared by someone who had the basic knowledge of what they were doing. A thorough analysis of the entire structure revealed widespread failures in the model, further underscoring the absence of foundational understanding in the design process.
Another notable flaw was the significant reduction in column size at just the third-floor level, compromising the building’s load path. These reductions were significant enough to prove that whoever prepared this drawing failed to consider cumulative axial loads and moments acting on the structure, a mistake avoidable with a basic understanding of structural behavior. These cases highlight the pressing need to address the knowledge gap.
These findings reflect a pattern of lack of fundamental principles, often masked by the overuse of sophisticated analysis tools without proper or any validation. More alarmingly, these oversights are only detected only during peer reviews, not during the initial design phase.
Why the Disconnect Exists
The challenges facing structural engineers today are multifaceted. Academic programs often emphasize theoretical analysis, focusing on complex mathematical approaches. While these are essential, they often overshadow practical skills such as intuitive judgment, conceptual modeling, and preliminary sizing.
Furthermore, the rise of computational tools has created a dependency that discourages manual checks. Engineers frequently trust software outputs without questioning their validity. This reliance erodes the ability to “see” how a structure behaves, a skill that can only be honed through hands-on experience and repeated practice.
Another factor is the increasing specialization within the field. Engineers often focus on narrow areas of expertise, reducing their exposure to holistic structural behavior. This compartmentalization creates blind spots, as engineers may lack the broader perspective needed to anticipate problems.
The Education Gap
Education is a culprit. Many universities prioritize teaching complex analytical methods over developing deep understanding of structural behaviour. The justification for teaching topics with no practical relevance in the design office is often framed as a need for young engineers to know them. Perhaps the old saying remains true: changing a syllabus is harder than moving a graveyard. Feedback from recent graduates reveals that topics like deflected shapes and bending moment diagrams are only briefly introduced but rarely revisited. As a result, graduates often enter the workforce with limited practical skills.
The ‘Brohn Test,’ a diagnostic tool assessing engineers’ understanding of structural behavior, highlights this issue. Over the years, average test scores have declined, with many engineers unable to correctly sketch moment diagrams even for a basic structure. This decline underscores the urgent need for a paradigm shift in engineering education.
The lack of hands-on practice exacerbates this problem. Students often rely on idealized examples in textbooks, which will not always reflect the complexities of real-world scenarios.
Practical Approaches to Improve Understanding
To cultivate the “feel” for structures, engineers must integrate practical learning with theoretical knowledge. Here are actionable strategies to achieve this:
Hands-On Training
The use of physical models, such as plastic strips or foam boards, is a practical and effective way to develop an engineer’s intuitive grasp of structural behavior. By bending or applying loads to these models, engineers can observe deflected shapes and load paths, gaining immediate, tangible insights. For instance, a plastic strip representing a beam can vividly demonstrate how span length or thickness affects its response to forces, reinforcing key concepts like bending and shear.
These exercises are equally valuable in classrooms and professional settings. Educational institutions can incorporate them into structural mechanics courses, while engineering firms can use them for staff training. Paired with theoretical calculations, hands-on modeling strengthens the ability to validate designs and fosters the critical skill of predicting a structure’s behavior before relying on computational tools.
Preliminary Sizing Exercises
Regularly estimating structural member sizes using basic rules is a foundational exercise for developing engineering intuition. Quick calculations, such as approximating beam depths or column dimensions based on span lengths and loads, help engineers internalize key principles of structural behaviour. For example, using rules of thumb to size a beam for a given span provides a preliminary sense of feasibility before detailed analysis begins.
This practice is invaluable for both students and professionals. Incorporating preliminary sizing into daily workflows or academic assignments, no doubt, complements detailed computational analysis with a stronger intuitive grasp. Over time, this habit sharpens judgment, enabling faster error detection and more efficient design decisions.
Balanced Software Usage
Computational tools should serve as a supplement to engineering judgment, not a substitute. While software provides precision and efficiency, it is essential to cross-check its outputs against preliminary estimates derived from basic principles. This ensures that the results align with the expected structural behavior and helps identify potential errors or unrealistic assumptions in the model.
Continuous Professional Development
The most salient skill of an engineer is recognizing what they don’t know and taking steps to address those gaps. Continuous professional development (CPD) plays a vital role in helping engineers enhance their understanding and stay updated with evolving practices.
By engaging in CPD activities, engineers can refine their judgment, deepen their intuitive grasp of structural principles, and stay aligned with modern advancements. This commitment to lifelong learning not only strengthens individual expertise but also elevates the overall quality and safety of engineering practice.
Staying Within the Limits of Competence
Finally, a critical yet often overlooked aspect of preventing faulty designs is ensuring that engineers operate within the boundaries of their expertise. Structural engineering, like all branches of the profession, demands specialized knowledge and practical experience. Attempting to handle tasks outside one’s area of competence can only end in one way – disaster!
Rather than dabbling in unfamiliar territory, engineers should seek collaboration or guidance when needed. A recognition of your limitation is not a sign of weakness but a sign of upholding ethical standard.
Conclusion
Understanding structural behavior is not just a technical skill; it is the essence of competent engineering. It ensures safe, efficient, and sustainable designs while empowering engineers to master their craft
Reviving the “engineer’s feel” for structures requires commitment from all —educators, employers, and engineers themselves.
See: [Viewpoint] What Makes a Good Engineer?
Sources & Citations
- Institution of Structural Engineers (IStructE). (2020). Code of Conduct. Retrieved from https://www.istructe.org.
- Brohn, D. (2013). Understanding Structural Behaviour. 3rd Edition. ICE Publishing.
