Strength of Materials, Thinking outside the box
Strength of Materials, Thinking outside the box
Embedded Files
2024/2025 Q2 Universitat Politècnica de Catalunya - BarcelonaTech (UPC)
2024/2025 Q2 Universitat Politècnica de Catalunya - BarcelonaTech (UPC)
Posted by | Milad Soltanalipour | 2025/07/06
The final course projects of this academic year 2024/25 Q2 have gone beyond expectations. For their final course project of Strength of Materials, GTIAE students have delivered surprisingly good works, combining the theory of Strength of Materials with budget-conscious and eco-friendly solutions.
In this article, you’re invited to take a look at the top 5 projects to figure out why they stand out from an academic point of view.
Strength of Materials is a subject within the framework of Industrial Engineering and Economic Analysis bachelor's degree program at the Universitat Politècnica de Catalunya.
Top 5 course projects
Top 5 course projects
Compound M-shaped cross-section
Compound M-shaped cross-section
Paula, Maria, Biel
Paula, Maria, Biel
10 out of 10
Lego-inspired joints applied on a wooden beam
Lego-inspired joints applied on a wooden beam
Pau, Mariona
Pau, Mariona
9.91 out of 10
Optimized I-section (variable width)
Optimized I-section (variable width)
Carla, Paula, Gerrard
Carla, Paula, Gerrard
9.33 out of 10
Optimized T-section (variable height)
Optimized T-section (variable height)
Arnau, Manuel, Enric
Arnau, Manuel, Enric
9.17 out of 10
Optimized T-section (variable height)
Optimized T-section (variable height)
Jara, Bea, Inés
Jara, Bea, Inés
9.14 out of 10
Figure 1. M-shaped cross-section
Paula, Maria, Biel
Figure 2. Lego-inspired joints
Pau, Mariona
Figure 3. Innovative design of a curved beam
Bruno, Gerrard, Guillermo
Cross sections
Cross sections
Students are asked to design and build up a cross-section for their final project structure. There are infinite possibilities of dimensions that match the required section modulus, even-though the problem statement defines some dimensional limits that narrow down the possible options on the desk.
A novel solution introduced this year is an M-shaped compound section, created by welding two inverted U-profiles together (see Figure 6 for the welding process).
Figure 4. Original section, H, I and M sections
Paula, Maria, Biel
Figure 5. Compound M-shaped section
Paula, Maria, Biel
Figure 6. Building up the M cross-section
Paula, Maria, Biel
The original section that Paula, Maria, and Biel had was a tubular profile. However, they decided to build a new section based on the original one, since commercial sections are not allowed for the final course project.
They evaluated three possible configurations (see Figure 4 for details) and selected the M-shaped profile. The other options were either excessively slender (H > 2B) or not optimal in terms of moment of inertia.
For the course project in the subject Strength of Materials, the cross-section can be solid (e.g., rectangular, valid only if variable), hollow (e.g., tubular sections), or even open thin-walled sections (e.g., I or T sections). However, commercial profiles are not allowed. If all the elements are already connected, it becomes impossible to calculate the required welding length or determine the size, number, and spacing of screws.
It is recommended to use sections whose principal axes of inertia are aligned with the global Y and Z axes. For example, an L profile is not a suitable choice, as its principal axes do not coincide with the global axes, resulting in a biaxial bending problem.
Figure 7. Possible sections
Berta, Paulina, Blanca
Table 1. Qualitative comparison of section shapes
Edu, Gerrard, David
Lighter, or stronger,
that is the question.
Lighter, or stronger,
that is the question.
The degree of efficiency adds a competitive edge to this project. To illustrate it in simple terms, imagine two structures that can resist the same load—one made of wood, the other of steel. The wooden structure is more efficient because it achieves the same performance with less weight.
Efficiency, in this context, refers to how much load a structure can carry relative to its own weight. It is calculated as the ratio of nominal load to weight (P/w).
In the following bar chart, each group’s degree of efficiency is presented.
Figure 8. Degree of Efficiency of course projects, semester 2024/25 Q2, Strength of Materials
As a general rule, the grade assigned to course projects is independent of the material chosen. Students are free to use any material to construct their beam—wood, PLA (3D printing), steel, aluminum, or others. However, the degree of efficiency (P/w) does influence the final grade (see next figure). Groups with a higher P/w ratio typically receive a better mark for this part of the evaluation.
Figure 9. Grade versus degree of efficiency, semester 2024/25 Q2, Strength of Materials
Figure 10. Smiley face of dynamometer, Weight measurement of the structure
Carla, Paula, Gerard
Reinforcing joints with 3D printed elements
Reinforcing joints with 3D printed elements
As the beam is not straight, there are joints where the geometry of the structure changes. These joints are often the weakest parts due to stress concentration. Several strategies can be used to reduce this effect: adding fillets or curved corners, minimizing sharp angles, and reinforcing the joints.
Pau and Mariona have designed an interesting reinforced joint and 3D printed it. Their design is inspired by Lego elements, taking advantage of the mechanical interlocking between components.
In addition, the joint is glued to the wooden beam to prevent failure due to longitudinal shear between the wood and the PLA. Notice how the fiber directions have also been aligned with the normal stresses.
It is a very simplified design, but simplicity is sometimes the most difficult to achieve.
Figure 11. Lego-inspired joints
Pau, Mariona
Figure 12. Lego-inspired joints
Pau, Mariona
ANSYS Simulations
ANSYS Simulations
Two types of Finite Element (FE) simulations have been performed by GTIAE students: either 2D or 3D, the majority using ANSYS Mechanical software.
A 2D FE simulation using BEAM elements is typically used to verify manual calculations, such as internal forces and moments, stresses, and displacements.
In contrast, a 3D FE simulation using SOLID elements is more suited for analyzing stress distributions at joints, identifying critical sections, or studying displacements in beams with variable cross-sections.
A simulation using BEAM elements is relatively easier to carry out, as it only requires the position of the neutral axis and the geometrical properties of the cross-section. In contrast, a simulation with SOLID elements involves creating the full 3D geometry—either directly in ANSYS or by importing it from other software in .IGS format.
This means that if the goal is to perform a parametric FE study (e.g., to analyze the effect of different dimensions), a 2D model with BEAM elements is often a more practical choice. In 3D with SOLID elements, each change in geometry would require updating the .IGS file, re-importing it into ANSYS, and restarting the simulation process.
Figure 13. 3D FE simulation using ANSYS (SOLID element type)
Jara, Bea, Inés
Figure 14. Optimized T-section with variable height,
Jara, Bea, Inés
The sky's the limit
The sky's the limit
GTIAE students have pushed the boundaries of innovation in their final projects even further than in previous years. For instance, as the following figures show, the use of curved structures has clearly increased compared to past semesters.
Figure 15. Beam layout options
Yago, Clara, Mariona
Figure 16. Brilliant idea
Bruno, Gerrard, Guillermo
One of the main reasons for using curved corners is their ability to reduce stress concentrations at joints. From a constructional perspective, the increasing accessibility of 3D printers—such as those available at EngiLab—is also driving interest in curved beam designs and gradually changing the rules of the game.
If you’re considering curved beams for your course project, here’s a theoretical tip: internal forces and moments can be expressed as functions of the angle rather than the coordinate x. This approach is more suitable for curved geometries, as it simplifies the analysis. Similarly, displacements can be calculated using angular differentials instead of x, with the limits of integration defined in radians.
To characterize the chosen material, our laboratory LERMA provides students with tensile or bending test results from their own samples.
Figure 16. Lab. Technician performing a steel tensile test at LERMA
Maria Eduardo, Didac, Marta
Figure 17. Three-point bending test, before and after test
Laia, Federico, Nahia
Theory part
Theory part
The theory part accounts for the majority of the final grade, as the main goal of the course project is to apply knowledge from the theory classes to a practical case.
The basic theoretical analysis typically includes internal force and moment diagrams, stress calculations at the critical section, safety factor determination, failure load estimation, and displacement analysis. A simple design supported by a thorough theoretical analysis generally receives a higher mark than a highly innovative design that lacks fundamental theoretical work.
Figure 18. Free Body Diagram of the problem
Arnau, Manuel, Enric
Figure 19. Final technical drawing, Arnau, Manuel, Enric
Summary of course project
Summary of course project
This is an experimental project where students are asked to design, build, and test a structural element. The objectives are to learn how to apply Strength of Materials principles in practice, develop teamwork and time management skills, and make budget-conscious and eco-friendly decisions.
In the final laboratory session, the structure is tested by applying a load up to a nominal value, which the structure is expected to withstand. Reaching the nominal load generally indicates that the group has done a good job.
Additionally, the measured deflection should not exceed a specified limit, typically 15 mm. This deflection is carefully measured using a displacement sensor. Another requirement is that the structure must not come into contact with two box-shaped obstacles (see Figures 15 and 16).
Page updated
Report abuse