basic interview questions for mechanical designer
1. What are the failures with reference to the structural design?
Failure of a structural part can occur by :-
A. Excessive elastic deformation.
B. Excessive non- elastic deformation.
C. Fracture.
Any design has to guard against these perceived failures.
2. What are the factors upon which the mechanical properties of material are dependent?
Mechanical properties of any material of construction are dependent on :-
A. Chemical composition of the material.
B. Method by which the material is manufactured.
3. What is stress?
It is defined as the applied load per unit cross-section of the specimen. The common unit are psi (pound per square inch), kpa, Mpa, kg / cm
4. What is strain?
For tensile load, it is the proportional change in length of the specimen under constant sustained load to its original length before loading is done. For tensile load, it is the ratio of the decrease in length to the original length when the load is sustained.Strain is thus an observable and measurable quantity as the extension or compression of the specimen can be directly measured. It is a dimensionless quantity.
Mechanical engineering interview questions with answers
5. What is the upper yield point with reference to the above stress-strain graph (Ultimate Tensile Strength)?
The highest stress that the metal can withstand under sustained load without continuing to elongate under the same load is called the upper yield point.
6. What is allowable stress?
It is defined as ultimate tensile strength divided by factor of safety. The safety factor is obviously greater than 1. Designs which ensure that the stress value anywhere in the structure is less than this allowable stress are considered safe as they do not allow the structure element to come anywhere close to the point where plastic instability leading to disruption or disintegration of element would set in.
7. What is the value of allowable stress if yield stress or 0.2% proof stress value is available at design temperature?
If the yield stress or 0. In the case where the 2% proof stress value is available at the design temperature, the same shall be divided by a factor of safety of 1. This paper is divided into five sections to arrive at allowable stress.
8. What is the value of allowable stress if the yield stress is not available at design temperature but is available at room temperature?
In case, the yield stress is not defined at design temperature but is given at room temperature, the latter shall be divided by a factor of 3. Therefore, the design stress is achieved at 0 to get allowable stress.
Interview questions and answers for mechanical design engineer
1. How much design temperature shall be considered for the structural parts which are heated by steam, thermic fluid etc?
Design temperature shall be the highest expected temperature of the heating media or highest expected body part temperature plus 10C. Here, 10 C is the safety margin.
2. Define proof stress?
It is also called 0.2% proof stress. It is the stress for 0.2% strain. In simpler terms, it is the stress value for strain value of 0.002 on the stress strain curve.
3. What are the types of failures encountered in Piping?
1. Catastrophic failure. 2. Fatigue failure.
4. Define catastrophic failure?
The failures which occur suddenly as soon as the load crosses the threshold (ultimate tensile strength). These failures take place on the first occurrence of the loads in excess of yield stress.
5. What is fatigue failure?
The failure occurs due to damaging of the grain structure of the specimen subjected to prolonged application of sustained load and or tensile–compressive load cycle.
mechanical engineering interview questions and answers
6. What are the types of fatigue failure?
Types of fatigue failure are:-
A. Static fatigue.
B. Cyclic fatigue.
7. What is static fatigue?
The specimen which fails under sustained load is subjected to considerable length of time. The total time for which the load was applied is important. Whether it is applied continuously or in installments is not important.
8. What is cyclic fatigue?
The specimen which fails under a load cycle is subjected to considerable numbers of times. The total number of cycles for which the load was applied is important. Whether the cycle was frequent or infrequent is not important.
9. Explain the failure of the specimen subjected to cyclic load?
Consider a specimen subjected to a tensile load increasing from zero to X and then this load is gradually withdrawn till it is zero. Now the compressive load is applied gradually till it is X and then it is drawn till the load is zero. This comprises a cycle and is repeated again and again. With each cycle, the grains in the material get displaced relative to each other and get more and more interlocked. With each cycle, the material loses its ductility in small increments. A time comes when the grains are so badly interlocked that they cannot allow deformation to withstand load and a small crack develops. This crack grows with further cycles and failure occurs.
10. What is creep failure?
Occurrence of static fatigue failure when the material is under prolonged sustained load coupled with high temperature is called creep failure.
11. Write the sequence of stress values at failures for solid rod, sphere and cylinders?
A typical sequence of stress values at failure for solid rods and two most important shapes in the process industry namely, sphere and cylinder is Rod > Sphere > Cylinder.
How to prepare for mechanical design engineer interview
To prepare for a mechanical design engineer interview, you should:
- Review your resume and highlight your most relevant skills and experience.Be ready to talk about when you used this or that design software, when you applied certain engineering concepts, and how you dealt with manufacturing issues.
- Research the company and the role you are interviewing for.This will assist you establish the requirements of the company and in what ways and why your abilities will be a great match.
- Practice answering common mechanical design engineer interview questions. Again there’s many books and online resources you can use for this should you by any chance not know how to do so.
- Be prepared to discuss your design process and how you approach problems. Interviewer will expect to find a profound and systematic way of thinking, especially in terms of design and critical problem solving.
- Be confident and enthusiastic.Make the interviewer see that you are interested in the opportunity and that you are sure you can be an addition to the job.
Here are some specific tips for answering common mechanical design engineer interview questions:
- When asked about your experience with specific design software, be specific about your skills and experience.For instance, if you are asked about your experience in a certain software such as SolidWorks, you could express yourself thus: I’m conversant with the use of this software in developing 3D mechanical parts.
- When asked about your engineering principles, be able to explain them in a clear and concise way. For instance, should a learner be questioned on conservation of energy, he/she may respond that, according to this principle energy cannot be created or destroyed but it can be transferred.
- When asked about manufacturing processes, be able to discuss the different types of manufacturing processes and the advantages and disadvantages of each process.For instance, a topic of comparison may involve casting and machining, and looking at this point how each process might be useful in the production of different parts.
- When asked about your design process, be able to describe the steps that you typically follow when designing a new product or component.For instance, you could speak as follows: It is common to proceed from establishing the requirements, coming up with the conceptual design, proceeding to detail design, making a prototype and testing the same.
- When asked about how you approach problems, be able to explain your problem-solving process.For instance, you may venture to describe your working through it approach, as follows: First, there is problem definition, followed by the identification of potential solutions, third is the comparison of solutions with selection of the best one, and lastly is the implementation of the whole course of action.
Applying these tips, one will be well prepared to attend a mechanical design engineer interview and have increased likelihood of passing it.
Basic interview questions for mechanical design engineer
Coming to an interview for the job of Mechanical Design Engineer, it is important that the candidate is prepared to talk about oneself’s qualifications, experience, and problem-solving skills and technical knowledge. Below are some basic interview questions that you might encounter:
Can you describe your background and experience as a Mechanical Design Engineer?
- Summarize your education, work experience and talk about any projects that have been executed to the best of your knowledge.
What software tools are you proficient in for mechanical design?
- Again, you could name such programs as CAD (Computer-Aided Design) tools, FEA (Finite Element Analysis) software, and others software that would be used depending on a certain industry.
How do you approach the design process for a new product or component?
- Describe the process regarding idea generation for the project as well as the creation of a prototype, assessment, and improvement.
Could you provide an instance of a challenging design problem you have encountered and how you solved it?
- It is important to illustrate a real-life experience or a case and explain how it is addressed, the critical issue in it, the solution given and how it was arrived at.
What engineering standards and codes are you familiar with, and how do you ensure compliance in your designs?
- Explain what other standards and codes to follow such as ASME, ISO or other differentiated industrial codes you need to follow; show your procedure in compliance.
How do you handle design changes or modifications requested by clients or stakeholders?
- Explain how to approach change in design requirements continuing to adhere to the schedule and cost estimates.
What materials selection criteria do you consider when designing a mechanical component?
- Discuss requirements such as the type of material, the cost of the material, how long it would last, and the effect the material has on the environment.
Explain the importance of tolerance and how you ensure components fit together correctly.
- Describe as much as you recall about GD&T and how it is still beneficial in design work and in what ways.
Have you worked on projects that involve three dimensional printing or additive manufacturing?
- Explain any application that has been made using the emerging manufacturing technologies and the effects on the design process.
Can you discuss your familiarity with simulation and analysis tools for structural or thermal analysis?
- State any experience with the kind of tools such as, ANSYS, SolidWorks Simulation or any other similar tool.
How do you stay updated with the latest advancements and trends in mechanical design and engineering?
- Emphasize numerous opportunities to learn and improve qualifications as well as organizational loyalty.
Have you worked on cross-functional teams or collaborated with other departments (like, manufacturing, quality control)?
- Explain your experience in working in a team and communicating in a multifunctional engineering setting.
Describe a situation where you had to balance design innovation with cost constraints.
- Demonstrate your capacity to make actual decisions in the design and style of the work while ensuring the functionality of the final product.
Can you provide an example of a successful project where your design improved efficiency or reduced waste?
- Share a project that made a difference in cost savings or improvement of the process.
How do you handle unexpected design challenges or setbacks during a project?
- Explain that you will describe your ability to be flexible in the workplace and find solutions to solve unexpected situations.
What do you enjoy most about mechanical design engineering, and why are you passionate about this field?
- State that you are attracted to the profession and you want to do an excellent job in the position.
Also, do not forget to include your various samples that endorse your skills and experience derived from the practical sessions. So, answer the questions with efficiency as to the definite type of job which you are going to get and be ready with the technical questions and discussion of how your engineering profession was used.
Mechanical engineering interview questions for freshers
Here are some mechanical engineering interview questions that are commonly asked to freshers:
- What are the different categories of forces?
- What is the difference between Stress & Strain?
- What is the conservation of energy principle all about?
- What is the difference between Static Analysis & Dynamic Analysis?
- What is the difference between a Machine Element & a Structural Element?
- What are the different types of Manufacturing processes?
- What is the difference between Casting and Machining?
- What is the difference between CAD model & FEA model?
- What is the difference between Prototype & Production part?
- What are the different types of Quality Control Methods?
- What is the difference between Tolerance & clearance?
- What is the difference between Fit & Clearance?
Apart from these technical questions, the mechanical engineering interviewers may also pose questions on form specific software like SolidWorks or MATLAB. They may also like to know about the candidates’ behavior, working in groups, effective communication, and methods for solving problems.
Here are some specific tips for answering mechanical engineering interview questions for freshers:
- It is recommended to be honest and specific about one’s experience. Never attempt to fake your knowledge on questions that you do not have an idea about.
- Mechanical engineering should be enjoyed and done with much passion. Dress in a neat and professional manner and smile to show enthusiasm and also make sure that you are well prepared, confident and ready to learn.
- Describe how you came up with the answer. When answering questions, you should also be able to illustrate how you got to your answer. This makes the interviewer see that once given a certain task you can analyze it and come up with a solution.
- Understand the theoretical concepts and learned concepts and be able to relate them with situations in the real world. While answering the questions it is advisable to make use of real-life examples as much as possible. This tends to make the interviewer realize that you are conversant with the information you are teaching and you are capable of applying the knowledge in a real life incident.
Thus, it is important to learn about the company, specific questions that may be asked, and how to answer them to help you succeed in a mechanical engineering interview.