Dent Testing Machine

The dent resistance has become an important design parameter for automotive outer body panels due to the increased use of thinner gauge high strength steels for fenders, hoods, and decklids, for vehicle weight reduction purposes. The history of assessment of dent resistance dates back to 1974 wh

Project Title

Dent Testing Machine

Project Area of Specialization

Mechanical Engineering

Project Summary

The dent resistance has become an important design parameter for automotive outer body panels due to the increased use of thinner gauge high strength steels for fenders, hoods, and decklids, for vehicle weight reduction purposes.
The history of assessment of dent resistance dates back to 1974 when Dicello and George assessed the static dent resistance of panels. They studied the effect of panel stiffness and yield strength on the dent resistance of automotive body panels. After that, 100s of researches were conducted on dent resistance by different scientists like Chi-Mou Ni, M. Kojima, and Y. Hayashi. The history of dent resistance testing is not too old, but it has significance in the automotive industry.
Dent testing machines are not readily available in Pakistan. Either they are extremely rare or expensive to purchase. That's why we want Pakistan to make its dent testing machines. We have stepped forward to design and developed dent testing machines in Pakistan.
We are going to follow the international standard of the Society of Automotive Engineers (SAE) for dent testing procedures (J2575), which is also followed by General Motors. Our machine would be capable of doing dent resistance test according to the international standard.
We would use a hydraulic system controlled by Arduino. The load and dent depth would be measured using a load cell and displacement transducer, respectively. Our controller would capture and process the data coming from our sensors and, the result would display on an LCD screen.

Project Objectives

The automotive industry is optimizing the design to reduce weight for better fuel economy. Several performance criteria must be met for optimized design which includes stiffness, buckling, dent resistance, etc. Our aim or main focus in this particular project is on dent resistance. For this purpose, we are developing a dent testing machine that will test our sheet metal. The machine can perform under static and dynamic conditions. These methods will provide reproducible and comparable dent results. It will give a complete report through which we can analyze and make modifications to our outer panel. Another objective of developing this machine is that it can be utilized at the university level for Learning purposes. The student will gain practical knowledge about dent resistance and how things work. The dent resistance equipment may in the future be used in performance predictions and quality control issues.

Project Implementation Method

Quasi-Static Dent Evaluations

General Requirements

We will make arrangements in test frame, actuator, stiffness, intenders, speed, test system, load cell and displacement transducer, calibration, and appropriate hardware.

General Test Procedure

INCREMENTAL DENT RESISTANCE EVALUATION TEST SEQUENCE

First, we will apply a pre-load of 7 N. Then we will unload back to 0 N. Then we will apply a load of 50 N and then unload to 0 N again. Then again we will apply 70 N and again back to 0 N. same, we will do till 210 N and back to 0 N. Then we will apply post load of at least 7 N.

HARD OIL CAN EVALUATION TEST: TEST SEQUENCE

Almost done with the same method by 10 N difference.

Data Analysis

Incremental Dent Test loading sequence

First, we will determine zero displacement at 5 N. Then determination of resulting dent depth will occur. Then the interpretation of critical denting load will be done. Then hard oil can evaluation test will take place. Then oil canning load will be found.

Full Dent Characterization

In this system requirements of a 3D dent, profiling equipment will perform according to minimum diameter, resolution, and accuracy. Then we will prepare the panel. An analysis area of 102mm x 102mm will be used.

In the end, we will make records and reports.

Dynamic Dent Evaluations

General Requirements

We will make arrangements in test frame, actuator, stiffness, intenders, speed, test system, load cell and displacement transducer, calibration, and appropriate hardware.

General Test Procedure

TESTING ON EQUIPMENT WHICH CAN MEASURE AND RECORD COMPLETE LOAD-DISPLACEMENT: TEST SEQUENCE

First, we will apply a pre-load of 7 N. Then we will unload back to 0 N. Then the sample is indented with 0.2 J and retracted back to 0 J. Then applying post load of 7 N and comes back to 0 N. Same we will do till 0.5 J.

TESTING ON EQUIPMENT WHICH CAN MEASURE AND RECORD ONLY IMPACTING ENERGY AND FINAL DENT DEPTH: TEST SEQUENCE

The almost same method will be used with some variations.

Data Analysis

TESTING ON EQUIPMENT WHICH CAN MEASURE AND RECORD COMPLETE LOAD- DISPLACEMENT

First, we will determine zero displacement at 5 N. Then determination of resulting dent depth will occur. Then we will test on equipment that can measure and record only impacting energy and final dent depth.

Full Dent Characterization

In this system requirements of a 3D dent, profiling equipment will take place of minimum diameter, resolution, and accuracy. Then we will prepare the panel. An analysis area of 102mm x 102mm will be used. 

In the end, we will make records and reports.

Benefits of the Project

In recent years, strict weight reduction targets have pushed auto manufacturers to use lighter gauge sheet steels in all areas of the vehicle including exterior body panels. As sheet metal thicknesses are reduced, the dent ability of body panels becomes of increasing concern. Thus, the goal becomes one of reducing sheet metal thickness while maintaining acceptable dent resistance so to assess the dent resistance of different automotive body panels and structure a dent testing machine is used. This machine is not available all over in Pakistan and that is why it is very difficult for different industries related to mechanical and automotive and they apply some different techniques and methods to check the dent resistance of different automobile body panels so by looking at the severity of this problem we Final Year Students took this initiative to develop this machine and as a result of the development of this machine, it will provide the following benefits to different automotive industries and it will be a huge accomplishment for Pakistan.
1.    We can apply different static and dynamic loading conditions to our body panels and structures and can check its dent resistance and can predict that how the specimen will respond at the applied loading condition.
2.    This apparatus can be also be deployed at the university level where students can perform different experiments and can get a sound knowledge of the working principle of this machine.

3.    This machine also has another benefit that the bending stiffness of different body panels can be calculated and by this we can easily predict that how much load that body panel will support.

4.    The other major benefit of this apparatus from an industry point of view is that it will significantly reduce the overall cost of procurement of process equipment and then we can develop this machine locally as well.

Technical Details of Final Deliverable

PRODUCT NAME

DIMENSIONS

MATERIAL

TARGET PRICE (RS)

PRODUCT WEIGHT

DISPLACEMENT TRANSDUCER

LOAD CELL

HYDRAULIC CYLINDER

ADRUINO UNO

HYDRAULIC PUMP

INDENTER/PUNCH

LCD DISPLAY

AMPLIFIER

PIPES

SHEET METAL

Final Deliverable of the Project

HW/SW integrated system

Core Industry

Transportation

Other Industries

Core Technology

Internet of Things (IoT)

Other Technologies

Sustainable Development Goals

Industry, Innovation and Infrastructure

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com