Introducing "advanced" tuned vibration absorbers in an undergraduate vibrations course

The primary objective of this paper is to bridge the theory of tuned vibration absorbers (TVA) with the practice of implementing TVAs in systems. Often, the practice of implementing TVAs in systems is a far departure from the theory expressed in many textbooks. These departures are often required in practice to account for the less than ideal conditions that the TVAs will be operating under. Many retrofitted TVAs use "smart" or active materials along with various control techniques to improve the performance of the traditional TVA proposed in textbooks. The intent of the current paper is to demonstrate several of these modern methods of implementing retrofitted TVAs to undergraduate students. The first author introduced the methods in a junior level vibrations course, and is developing a laboratory experiment. Teaching these advanced TVAs to undergraduate engineering students will help them understand how theories learned in class are used in real world problems, and motivate them to explore new fields of research. After introducing a "textbook" vibration absorber theory, this paper describes principles and operations of a new class of vibration absorbers. In reviewing conventional TVAs, students are introduced to many of the engineering challenges encountered in the implementation of TVAs. One such challenge is inevitable off-tuning caused by system parameter changes with time. After identifying many of the challenges associated with the implementation of TVAs, the students are introduced to many modern solutions to these problems. Many of these solutions involve the use of smart materials, such as piezoceramics, magnetorheological fluids, magnetorheological elastomers, shape memory alloys, etc. Through this experience, students are introduced to many smart materials and have the opportunity to see how these smart materials can provide solutions to many engineering challenges and improve existing technologies.