A global model of a piano is presented. Its aim is to reproduce the main vibratory and acoustic phenomena involved in the generation of a piano sound from the initial blow of the hammer against the strings to the radiation from soundboard to the air. One first originality of the work is due to the string model which takes both geometrical nonlinear effects and stiffness into account. Other sign...

A multiple scales analysis is used to construct a uniformly accurate approximation to water hammer pressure wave attenuation that is initiated by a sudden valve opening. The method of analysis is well suited to the study of a water hammer that possesses several time scales and is applied to a mild generalization of the classical equations. It should prove useful for finding attenuation curves w...

Abstrak
 Hammer test dianggap kurang akurat karena hanya menginformasikan kuat tekan beton pada permukaan saja. pelat arah vertikal ke atas dilakukan untuk menghindari pembongkaran penutup lantai. Jumlah titik pantul sesuai ketentuan dalam standar minimal 10, diupayakan dikurangi tanpa mengabaikan tingkat akurasi dengan variasi pola segiempat dan radial. Eksperimen bertujuan menentukan ber...

in this research the quality of walnut kernels under impact loading were studied. due to unavailability of specific varieties of walnut in iran, the tests were carried out on the available genotypes. three different genotypes from walnut orchards of azarshar region were selected and were collected in 2009. a drop test device was designed and constructed to perform the experiments. the impact te...