ZHANG Longxin ¹, ZHANG Wenbin ², XU Han ¹, MA Yaxing ¹

(1. Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming 650500, Yunnan, China; 2. School of Mechanical and Electrical Engineering, 

Kunming University, Kunming 650214, Yunnan, China)

Extended Abstract:[Background and purpose] Yunnan Jianshui purple pottery is famous for its excellent quality of "firm as iron, bright as water, moist as jade, sound as chime". However, against the backdrop of continuous refinement of the production process, product innovation is relatively lagging behind. The current market is mainly dominated by traditional tea sets, tableware and vases and other rotary products, while the phenomenon of homogenization is prominent, which seriously restricts the further development of Jianshui purple pottery industry. In order to break through this bottleneck, the innovative application of Jianshui purple pottery in the field of musical instruments by combining modern technological means. Specifically, this study will design a suspended percussive body sounding musical instrument that was explored, aiming to demonstrate the potential of Jianshui purple pottery in product diversification, opening up new product directions and design ideas for the industry, and hence promoting its transformation and upgrading.[Methods] ANSYS engineering simulation software was used to analyze the vibration characteristics of Jianshui purple pottery. In view of the fact that Jianshui purple pottery is known as "sound like a chime", its application to the design of musical instruments has a unique advantage. Specific research methods are described below.(1) Finite element modeling and modal analysis: ANSYS was used to establish a finite element model of a square thin plate of Jianshui purple pottery. Through free modal analysis, the first nine orders of intrinsic frequency and vibration pattern were calculated and extracted, so as to understand the basic vibration characteristics.(2) Parametric study: For key parameters affecting vibration characteristics, such as geometric dimensions (length, width, thickness) and material parameters (modulus of elasticity, density, Poisson's ratio), the degree of influence of each parameter was determined by varying a single parameter variable and observing its effect on the ninth-order intrinsic frequency (the frequency of interest in this study).(3) Derivation of empirical formulas: Based on the simulation data, the functional relationship between parameters and the ninth-order intrinsic frequency was established, while empirical formulas for the ninth-order intrinsic frequency under different thickness-to-length ratios were derived, which will provide a reference for the design of actual musical instruments.[Results] The intrinsic frequency of Jianshui purple pottery plate is closely related to the geometric parameters. Specifically, the smaller the thickness, the lower the intrinsic frequency. When the thickness is fixed, the longer the side length, the lower the intrinsic frequency. In addition, a set of square Jianshui purple pottery musical instrument plates, containing 12 pieces with tuning hole structures, were successfully designed. The range of this set of musical instrument boards was 2093–3951 Hz. The musical instrument samples were struck and analyzed by using MATLAB software for pitch, volume, duration and other musical performance indexes. The absolute error of pitch is less than 3 Hz, the range of volume is 50–75 dB and the range of tone length is 0.29–0.46 s.[Conclusions] The intrinsic frequency of Jianshui purple ceramic plates is highly sensitive to dimensional changes. In order to solve the problem of dimensional errors caused by the purple ceramic firing process or other factors, tuning holes at the four corners of the plate were designed and the mass distribution was adjusted by adding fastening mass components to realize the intonation correction. It was experimentally proved that this method can effectively overcome the dimensional error and ensure the accuracy of the musical instrument's intonation. The Jianshui purple ceramic pottery has been successfully applied to musical instrument design, while the "sound like a chime" property was verified and it's the potential in the innovative design of purple ceramic pottery musical instruments was demonstrated, thus opening up a new application field for the Jianshui purple ceramic industry and also providing a useful reference for the application of other ceramic materials in the field of musical instruments.

Key words: vibrations and waves; finite element analysis; intrinsic frequency; Fast Fourier Transform; natural frequencies; modal analysis