Chapter 1: Introduction
This chapter provides an overview of modal testing, its objectives, and applications. It also discusses the different types of modal testing and the key parameters involved.
Example: A company wants to investigate the vibration characteristics of a new product they are developing. They decide to perform a modal test to determine the natural frequencies, damping ratios, and mode shapes of the product.
Chapter 2: Theoretical Background
This chapter delves into the theoretical foundations of modal testing. It covers topics such as vibration theory, modal analysis, and data acquisition techniques.
Example: The modal test requires the measurement of vibration response data using accelerometers. The chapter explains the principles of accelerometer operation and how the data is processed to extract modal parameters.
Chapter 3: Experimental Setup
This chapter provides detailed guidelines on how to plan and execute a modal test. It includes discussions on instrumentation, excitation techniques, and data recording.
Example: The company selects a shaker excitation system to induce vibrations in the product. The chapter explains how to determine the appropriate excitation frequency range and amplitude.
Chapter 4: Data Acquisition and Analysis
This chapter describes the process of acquiring and analyzing vibration data. It covers topics such as signal conditioning, frequency response functions, and curve fitting techniques.
Example: The modal test involves measuring the vibration response of the product at various excitation frequencies. The chapter explains how to interpret the frequency response functions to identify the resonant frequencies and damping ratios of the product.
Chapter 5: Mode Shape Measurement
This chapter focuses on the measurement of mode shapes, which describe the deformation patterns of the structure under vibration. It discusses different techniques for mode shape measurement and their advantages and disadvantages.
Example: The company uses a displacement sensor to measure the mode shapes of the product. The chapter explains how to extract the modal displacements from the sensor data and how to visualize the mode shapes.
Chapter 6: Applications
This chapter presents real-world examples of how modal testing is applied in various industries. It covers applications in automotive, aerospace, civil engineering, and biomedical engineering.
Example: The company uses modal testing to optimize the design of their product to minimize vibration and improve performance. The chapter explains how the modal parameters obtained from the test are used in design modifications and simulations.
Chapter 7: Advanced Topics
This chapter explores advanced topics in modal testing, such as non-linear modal analysis, multi-degree-of-freedom systems, and model updating. It also discusses the use of modal testing data in finite element analysis (FEA).
Example: The company wants to investigate the non-linear vibration behavior of their product. The chapter explains how to perform non-linear modal testing and how to interpret the results.
