Vibration Training

Goal: How can I perform a simple mechanical environmental simulation with all components correctly without causing significant damage?

Prerequisite: You are familiar with the operating principle of the shakers.

Content: In Module I, you will discover the reason behind the “wobbling” of a shaker and receive an explanation of the “toolbox.” This toolbox contains essential knowledge needed for operating a shaker:

• Identification of necessary components for conducting a vibration test
• Understanding the consequences of misunderstanding the components and the resulting “wobble”
• Experience with the repercussions of attempting to outsmart physics
• Insight into the interdependencies of components and the consequences of neglecting these dependencies, especially when altering individual axes
• Development of skills to tackle challenges and understanding the mutual relationships in the application
• Exploration of the phenomenon of SINUS, where its simplicity is considered ingenious
• Understanding the concept of frequency response and its crucial role in shock absorber performance
• Examination of the delicate balance between shocks and being shocked, referred to as the SHOCK Strain
• Awareness of the importance of resolution and the underlying concept of “antialiasing”
• Analysis of the complexity of RANDOM and the question of whether everything truly happens at the same time
• Consideration of measurement uncertainty and its importance, despite trust in manufacturers
• Investigation into problem-solving and the principles that need to be applied, with the researcher as the main protagonist.

Goal: How do I perform a mechanical environmental simulation while considering failure analysis, normative declaration, and measurement uncertainty, and how can I evaluate and compare the results with similar tests?

Prerequisite: You are familiar with the fundamentals of vibration analysis.

Content: Do you work daily with a shaker and provide a conformity statement according to specific standards?

In Module 2, a step-by-step explanation is provided on how to learn the objectives of a test.

• Explanation of the purpose of vibration tests and understanding modal analysis.
• Learning to observe and understand errors.
• Introduction to the visible vibration theory.
• Understanding the conformity statement (standardization).
• Treatment of the main objective and benefits of a test, including understanding the significance of similar measurement results.
• Learning about the importance of measurement uncertainty analysis (MU) with practical examples.
• Recognition of errors in the test system and interpretation of possible errors and their causes.
• Insight into the interaction between sensor/control system/machine/clamping/human.
• Gaining insight and understanding to achieve the 10% goal.

Goal: How do I perform special cases of mechanical environmental simulation on large shakers correctly and reproducibly?

Prerequisite: Fundamentals of vibration analysis + measurement uncertainty + error analysis are known to you.

Content: Do you work with specimens that are so large that they cannot be fully attached to the traditional tables of a shaker?

In level 3, you discover the significance of the fact that the protruding parts of the inspected object must be “captured” by a well-designed fixture to eliminate undesirable effects.

• Learn how poorly designed fixtures can cause unwanted interference and how to deal with it.
• Understanding the use of so-called extensions/satellites to enlarge the clamping surface of the table.
• Insight into the concept behind it and its simplicity, but also its treachery.
• Acquire practical knowledge for mounting a test object over a very large surface.
• Learn to comply with normative requirements regarding fixtures.
• Gain tools to identify small causes that can have enormous effects.
• Learn various control strategies and subtleties related to sensors.
• Understand what rotational modes can do to a Device Under Test (DUT).
• Observation of the effect of a dynamic impulse on the overall system.
• Understanding dynamics and mechanical integrity.
• Observing the effect of thermodynamic effects and potential jamming issues, independent of the DUT.

Goal: The “right attachment” for my DUT on the shaker without distorting my test

Prerequisite: Fundamentals of vibration analysis + measurement uncertainty + error analysis are known to you.

Content: Do you attach your test pieces to the shaker and mount them on the shaker? Do you design your own fixtures and need to ensure that they are correctly mounted? Do you need to understand what the setup can do to your DUT?

In module 4, you will learn how to choose, determine, and develop the “right” attachment.

• Understanding the special significance of a fixture and the damage that can occur when ignoring physical rules.
• Experience with the transfer function and the impact of the fixture on the Device Under Test (DUT).
• Insight into the meaning of screw connections and why they are not a myth.
• Ability to determine the right material choice and understanding the relationship with damping and thermal expansion.
• Understanding the context in which the attachment influences the outcome of the test.
• Experience with slot holes and understanding their actual holding force.
• Experience with clamping force and understanding the interaction between deformation on the slip table and the resulting consequences.
• Knowledge of the calculation principles and construction skills needed to design fixtures correctly.

Goal: “Nature is not one-dimensional” – The big picture. The integration of movements and their effects!

Prerequisite: You already have fundamental knowledge of vibration testing and are familiar with some more specialized cases in the vibration testing world.

Content: Real systems generally have more than one degree of freedom and are rarely linear. We aim for a direct and clear understanding of lateral forces and how to deal with them.

In Module 5, you will learn how to “visualize” the operation of lateral forces and explain their connection to the test result.

• You will acquire in-depth knowledge of mechanical dynamics and their impact on the test result.
• You will see the visual representation of “harmful” lateral accelerations.
• You will gain expert knowledge on how to analyze more realistic problems in Single Degree of Freedom (SDOF) systems.
• You will learn how to investigate free oscillations in undamped linear systems with more than one degree of freedom.
• You will be provided with an illustration of forced oscillation in lightly damped linear systems with many degrees of freedom.
• You will recognize the causal effect of damping and understand the countless possible capabilities.
• You will identify the cause and effect of lateral forces in SDOF systems and understand the diversity of results that contribute to it.

Goal: Bringing the puzzle together – integrating all components and test elements to construct the “TEST CASE,” the one that is needed.

Requirements: You already have a fundamental knowledge of vibration testing and are familiar with some more specialized cases in the vibration test world, as well as with the general laboratory operation.

Content: Test finetuning is an approach to avoid errors, requiring a lot of know-how, but

• must be knowledge-based, and
• is the first choice when it comes to testing complex systems in a well-defined environment.

In Module 6, you will learn about environmental simulation and the influence of all components and test equipment with interaction, on and through the Device Under Test (DUT), in the context of the expected test result in mechanical vibration testing.

• You will learn the connection and experience the deepening of vibrations and the addition of factors of environmental simulation.
• You will learn which scenario needs to be taken to simulate the influences of the environment on technical products and reveal weak points.
• Q-Factor and what it means to understand this significance.
• You will learn to understand what FFT – Fast Fourier Transformation – means and why we need this to specify a test sequence.
• PSD – what does the Power Spectrum Density give us and what can we do with it?
• SRS – For which scenario is the Shock Response Spectrum suitable, and what statements can I make with it?
• FDS – What does the Fatigue Damage Spectrum mean? How do I deal with it? What can I test with this? Why do I need FDS at all?
• UDT – What possibilities does the User Defined Transient test sequence offer? Is this test sequence important for my products?