Interview Questions Every Design Engineer Should Know | Engineer’s Interview Blueprint

Ever wondered what it takes to secure a Design Engineer role at Plastic Omnium, one of the leaders in automotive components?  

If you’ve been prepping for an interview, you know it’s not just about knowing your technical fundamentals—it’s about applying those concepts in real-world scenarios.  

From designing with CATIA to understanding stress and strain in materials, the questions can span a wide range of topics, including practical tests with a time crunch. 

This blog will walk you through the real interview questions asked by Plastic Omnium for their Design Engineer role, offering insights into what they’re looking for and how to prepare effectively.  

So if you’re ready to tackle the challenges ahead and ace that interview, let’s dive in! 

Technical Questions and Answers: 

1. What is stress and strain, and what are their units? 

Stress is the force applied per unit area on a material (measured in Pascals, Pa), while strain is the deformation that occurs in response to stress (it has no unit, being a ratio of change in length to the original length). 

2. Explain the stress-strain graph. 

The stress-strain graph shows how a material deforms under stress. It features an elastic region (where the material returns to its original shape), a plastic region (where permanent deformation occurs), and an ultimate failure point called the fracture. 

3. What is creep? 

Creep is the gradual deformation of a material under constant stress over time, particularly at high temperatures. It's a key consideration in designing automotive parts that experience prolonged stress. 

4. Which sensors are commonly used in cars? 

Cars typically use a range of sensors, such as temperature sensors, pressure sensors, oxygen sensors, and proximity sensors, to monitor everything from engine performance to safety features. 

5. What is GD&T (Geometric Dimensioning & Tolerancing)? 

GD&T is a system that defines and communicates tolerances on engineering drawings. It ensures the correct fit, form, and function of parts by specifying allowable limits for size, position, orientation, and form. 

6. What is engineering drawing? 

Engineering drawing is a technical illustration that conveys information about the dimensions, materials, and assembly of a product. It’s a crucial tool for communicating between designers and manufacturers. 

Questions About Projects and Design Process: 

1. What do you know about our company? 

This is an opportunity to demonstrate your research about Plastic Omnium, including its work in automotive components, innovations in lightweight materials, and focus on sustainability and smart systems. 

2. What are flow lines and sink marks? 

Flow lines are visible lines on a molded plastic part, indicating the path of material flow during injection molding. Sink marks are small indentations caused by insufficient material cooling or uneven thickness. 

3. Draw the cross-section of a door trim panel. 

This involves sketching the inner layers of the door trim, showing materials like plastic, foam, and textiles, and highlighting key features like clips and fasteners. 

4. Explain one of your academic projects. 

Here, you’ll need to explain a project in detail, focusing on your role, the problem you solved, the tools you used, and the results. Relating it to real-world applications will make it more impactful. 

5. What are the steps and concepts behind designing your project? 

This question probes your design thinking—describe how you approached the problem, the tools and methodologies you used (like CAD or FEA), and how you iterated the design to improve performance. 

6. What is the product life cycle after your design? 

Once the design phase is complete, the project typically moves to CAE (Computer-Aided Engineering) and CFD (Computational Fluid Dynamics) analysis to validate the design before going into manufacturing. 

Mandatory Topics to Cover: 

• Strength of Materials (SOM): Critical for understanding the mechanical properties of materials used in the automotive industry. 
• Engineering Graphics: Vital for communicating designs effectively. 
• Material and Manufacturing Technology: Key for selecting materials that meet performance, cost, and manufacturability criteria. 
• GD&T: Ensures precision in part manufacturing. 
• Machine Design and Automobile Basics: Essential for developing automotive components that are both functional and reliable. 

Conclusion: 

The Design Engineer interview at Plastic Omnium is both a test of your technical knowledge and your ability to apply it in real-world scenarios.  

Remember, it's not just about knowing the right answers—it’s about showcasing your problem-solving skills, design thinking, and ability to work under pressure.  

Now, go out there and land that dream job! 

 With Skill-Lync's Post Graduate Programs, you'll build a rock-solid foundation in all these critical concepts, making you interview-ready in no time. Plus, our Career Experts offer hands-on support through mock interviews, resume workshops, LinkedIn profile optimization, and much more! 

Sign upfor a FREE course demo today, and let’s start our journey toward landing that dream job!