Ernst Chladni is called the father of acoustics for his work,which includes investigating patterns formed by vibrating plates.Understanding these patterns helps research involving standing waves and other harmonic beh...Ernst Chladni is called the father of acoustics for his work,which includes investigating patterns formed by vibrating plates.Understanding these patterns helps research involving standing waves and other harmonic behaviors,including studies of single electron orbits in atoms.Our experiment vibrates circular plates which result in well-known patterns.Alternatively to traditional experiments that used sand or salt,we use magnetic materials,namely iron filings and nickel powder.We then manipulate the patterns by applying a localized external magnetic field to one of the rings that moves a segment of the magnetic material in that ring to the next inner ring.The results show a significant decrease in magnetic field necessary to move the magnetic material at higher frequencies as well as a significant decrease in the magnetic field required to move the magnetic material as nickel powder is substituted for iron filings while keeping the mass constant.展开更多
The rim partials of a church bell (those with an antinode at the soundbow) generate the strike pitch or perceived note of the bell. The spacing in frequency of the higher rim partials has an important effect on the to...The rim partials of a church bell (those with an antinode at the soundbow) generate the strike pitch or perceived note of the bell. The spacing in frequency of the higher rim partials has an important effect on the tonal quality of the bell. Investigations into the partial frequencies of 2752 bells, both bronze and steel, of a wide variety of dates, founders and sizes, show a simple and unexpected relationship between the frequencies of the rim partials. This relationship explains why attempts to tune the higher rim partials independently have failed. A modified version of Chladni’s law provides insight into the musical relationship of the partials, and predicts the partials of individual bells well, but fails to give a simple model of the spacing between the partials seen in bells with different profiles.展开更多
Cymatics is a visual representation of sound and vibrations,on surfaces of plates,diaphragms,and membranes in the forms of auditory-images.The surfaces that are exposed to these vibrations are sprinkled with fine part...Cymatics is a visual representation of sound and vibrations,on surfaces of plates,diaphragms,and membranes in the forms of auditory-images.The surfaces that are exposed to these vibrations are sprinkled with fine particles that accumulate at nodes,to create visualizations of specific geometry unique to the particular frequency.This paper discusses the designing of an experimental platform,dedicated towards observing the behavior of cymatics,through analysis of such visualizations(Chladni patterns).This is further investigated by performing a numerical modelling using finite element simulation.Two millimeter thickness Aluminum(Al)plates of three shapes consisting of surfaces with equal areas were used for both experimental and finite element analysis(FEA).FEA was performed using ANSYS simulation software and patterns were derived for different vibrational frequencies.The results demonstrated that the 60%of the experimental imagery conforms with the visualization generated by ANSYS software.Additionally,the lowest average frequency differences with respect to the simulation results an average deviation for similar images was found to be 9.2%and 2.8 mm for the triangular shape plate,validating that the shape of the plate plays a paramount role in cymatics analysis.An image processing technique was used to determine the deviation between the images created by experimental platform and FEA for all the three shapes.The results demonstrate that Chladni patterns are best represented by a triangular shaped plate.展开更多
基金the support of SUNY Plattsburgh’s Internal Research Funds.
文摘Ernst Chladni is called the father of acoustics for his work,which includes investigating patterns formed by vibrating plates.Understanding these patterns helps research involving standing waves and other harmonic behaviors,including studies of single electron orbits in atoms.Our experiment vibrates circular plates which result in well-known patterns.Alternatively to traditional experiments that used sand or salt,we use magnetic materials,namely iron filings and nickel powder.We then manipulate the patterns by applying a localized external magnetic field to one of the rings that moves a segment of the magnetic material in that ring to the next inner ring.The results show a significant decrease in magnetic field necessary to move the magnetic material at higher frequencies as well as a significant decrease in the magnetic field required to move the magnetic material as nickel powder is substituted for iron filings while keeping the mass constant.
文摘The rim partials of a church bell (those with an antinode at the soundbow) generate the strike pitch or perceived note of the bell. The spacing in frequency of the higher rim partials has an important effect on the tonal quality of the bell. Investigations into the partial frequencies of 2752 bells, both bronze and steel, of a wide variety of dates, founders and sizes, show a simple and unexpected relationship between the frequencies of the rim partials. This relationship explains why attempts to tune the higher rim partials independently have failed. A modified version of Chladni’s law provides insight into the musical relationship of the partials, and predicts the partials of individual bells well, but fails to give a simple model of the spacing between the partials seen in bells with different profiles.
文摘Cymatics is a visual representation of sound and vibrations,on surfaces of plates,diaphragms,and membranes in the forms of auditory-images.The surfaces that are exposed to these vibrations are sprinkled with fine particles that accumulate at nodes,to create visualizations of specific geometry unique to the particular frequency.This paper discusses the designing of an experimental platform,dedicated towards observing the behavior of cymatics,through analysis of such visualizations(Chladni patterns).This is further investigated by performing a numerical modelling using finite element simulation.Two millimeter thickness Aluminum(Al)plates of three shapes consisting of surfaces with equal areas were used for both experimental and finite element analysis(FEA).FEA was performed using ANSYS simulation software and patterns were derived for different vibrational frequencies.The results demonstrated that the 60%of the experimental imagery conforms with the visualization generated by ANSYS software.Additionally,the lowest average frequency differences with respect to the simulation results an average deviation for similar images was found to be 9.2%and 2.8 mm for the triangular shape plate,validating that the shape of the plate plays a paramount role in cymatics analysis.An image processing technique was used to determine the deviation between the images created by experimental platform and FEA for all the three shapes.The results demonstrate that Chladni patterns are best represented by a triangular shaped plate.
基金the Full-time Introduction of National High-level Innovation Talents Research Project of Hebei Province(Grant No.2021HBQZYCSB003)the National Natural Science Foundation of China(Grant No.11832009).
