scholarly journals Pengukuran Modulus Young dengan Analisis Keadaan Resonansi Batang Aluminium yang Bergetar Menggunakan ImageMeter

Author(s):  
Maria Tefa ◽  
Ign Edi Santosa

<p class="AbstractEnglish"><strong>Abstract:</strong> An experiment to determine Young’s Modulus by analyzing the vibrations of an aluminum bar has been conducted. The aluminium bar is vibrated by the magnetic field. A tiny magnet is glued at the free end of the bar. A coil carrying an alternating current generates an alternating magnetic field. The resonance condition is investigated by the measurement of its wavelength using the ImageMeter application. The natural frequency of the aluminum bar is determined from the measurement of its resonance frequencies. The natural frequency and the bar length are used to calculate Young’s Modulus. The experimental data shows the Young’s Modulus of aluminum is . This measurement method is used for learning purposes.</p><p class="KeywordsEngish"> </p><p class="AbstrakIndonesia"><strong>Abstrak:</strong> Telah dilakukan pengukuran nilai Modulus Young dengan analisis getaran dari sebuah batang aluminium. Batang aluminium digetarkan dengan medan magnet. Magnet kecil ditempelkan pada bagian ujung batang aluminium yang bebas. Sebuah kumparan yang berada di bawah ujung batang aluminium  diberi arus bolak balik yang dapat diatur frekuensinya. Pada frekuensi tertentu akan terjadi resonansi dengan mengikuti pola yang khas. Keadaan resonansi batang aluminium ini dibuktikan dari hasil pengukuran panjang λ menggunakan aplikasi <em>ImageMeter</em>. Selanjutnya frekuensi alami batang aluminium ditentukan dari pengukuran frekuensi resonansinya. Nilai Modulus Young aluminium dihitung dari nilai frekuensi alami dan panjang batang. Dari hasil pengukuran diperoleh nilai Modulus Young . Metoda pengukuran ini digunakan untuk keperluan pembelajaran.</p><p class="KataKunci"><strong></strong><em><br /></em></p>

Author(s):  
Huiyu Li ◽  
Xufang Zhang ◽  
Hornsen Tzou

Light-activated shape memory polymers (LaSMPs) exhibit stiffness variations when exposed to ultraviolet (UV) lights. Thus, LaSMP could manipulate structural natural frequencies with UV light exposures when laminated on structures. This study aims to experimentally demonstrate the effectiveness of LaSMP frequency control of a flexible beam. The natural frequency of a three-layered Euler-Bernoulli beam composed of LaSMP, adhesive tape and the flexible beam is analyzed and its frequency formulation exhibits the LaSMP stiffness influence. As the LaSMP adopted in this study is a new spiropyran based composition, a generic Young’s modulus model is proposed and then simplified to model the present LaSMP composition. To make sure the experiment is carried out in a homogenous light field, the light intensities of the UV surface light source at different positions are tested. The temperature change of the LaSMP sample under UV exposures is also measured. The time constant of the reverse reaction and the threshold intensity of the reverse reaction are measured. LaSMP Young’s modulus variation is tested with a uniaxial tension experiment. The constitutive model of LaSMP’s Young’s modulus is validated by experimental data. With these preparations, the LaSMP laminated flexible beam model is exposed to the UV lights and its natural frequencies are identified with a data acquisition and analysis system. The maximum natural frequency variation ratio achieves 5.67%. Comparing both theoretical and experimental data of natural frequency control, this study also validates the LaSMP Young’s modulus constitutive model.


2005 ◽  
Vol 19 (07n09) ◽  
pp. 1360-1366 ◽  
Author(s):  
L. V. NIKITIN ◽  
A. N. SAMUS

The effect of a uniform magnetic field on the elastic and viscous properties of new magnetocontrolled materials (magnetoelastics) was studied. It was found that the application of a magnetic field leads to a considerable rise both in Young's modulus and in the viscosity of these materials. We investigated the samples prepared both in the absence of magnetic field and in the magnetic field applied during magnetoelastic curing.


2011 ◽  
Vol 675-677 ◽  
pp. 1159-1162 ◽  
Author(s):  
Bo Wen Wang ◽  
Wen Mei Huang ◽  
Ling Weng ◽  
Yu Fa Yi ◽  
Yan Ming Hao

The <110> grain oriented alloy was grown by zone melting directional solidification technique. The strain-stress curves of Tb0.3Dy0.7Fe2 <110> oriented alloy in different magnetic fields have been measured and the magnetic field dependence of Young’s modulus under different compressive stress has been confirmed. It is found that Young’s modulus gradually decreases with increasing the magnetic fields when the compressive stress is in the range of 15-25 MPa and changes a little in the range of 40-50 MPa. The experimental result indicates that the magnetic field has a marked effect on the Young’s modulus of the Tb0.3Dy0.7Fe2 <110> oriented alloy at a low compressive stress and its change should be considered during the design of magnetostrictive devices.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 968
Author(s):  
Fumitada Iguchi ◽  
Keisuke Hinata

The elastic properties of 0, 10, 15, and 20 mol% yttrium-doped barium zirconate (BZY0, BZY10, BZY15, and BZY20) at the operating temperatures of protonic ceramic fuel cells were evaluated. The proposed measurement method for low sinterability materials could accurately determine the sonic velocities of small-pellet-type samples, and the elastic properties were determined based on these velocities. The Young’s modulus of BZY10, BZY15, and BZY20 was 224, 218, and 209 GPa at 20 °C, respectively, and the values decreased as the yttrium concentration increased. At high temperatures (>20 °C), as the temperature increased, the Young’s and shear moduli decreased, whereas the bulk modulus and Poisson’s ratio increased. The Young’s and shear moduli varied nonlinearly with the temperature: The values decreased rapidly from 100 to 300 °C and gradually at temperatures beyond 400 °C. The Young’s modulus of BZY10, BZY15, and BZY20 was 137, 159, and 122 GPa at 500 °C, respectively, 30–40% smaller than the values at 20 °C. The influence of the temperature was larger than that of the change in the yttrium concentration.


Author(s):  
SHULEI SUN ◽  
XIONGQI PENG ◽  
ZAOYANG GUO

Polymer matrix filled with ferromagnetic particles is a class of smart materials whose mechanical properties can be changed under different magnetic field. They are usually referred to as magnetorheological elastomers (MREs). A finite element simulation was presented to describe the mechanical behavior of MREs with the nonlinearity of the particle magnetization being incorporated. By introducing the Maxwell stress tensor, a representative volume element (RVE) was proposed to calculate the Young's modulus and shear modulus of MREs due to the applied magnetic field. The influences of the applied magnetic field and the particle volume fractions in the shear modulus and Young's modulus were studied. Results show that the shear modulus increases with the magnitude of the applied magnetic field, while the Young's modulus decreases.


1960 ◽  
Vol 15 (3) ◽  
pp. 220-226 ◽  
Author(s):  
Klaus Körper

Radial oscillations are excited in a homogeneous infinite plasma cylinder in a homogeneous axial magnetic field by a surface current which is homogeneous in the axial and azimuthal directions. The modes of oscillations corresponding to the axial and azimuthal components of current are not coupled, and so they may be analysed separately. The magnetic field in the plasma and vacuum is obtained, and the indices of refraction for both types of oscillations are discussed thoroughly. When the currents are parallel to the external magnetic field, the oscillations are characterized by the refractive index of Eccles. On the other hand, when the current is perpendicular to the magnetic field two resonance frequencies exist, which depend on the density of the plasma and the magnetic field strength. — In the latter case the radial characteristic oscillations of the plasma cylinder in an external magnetic field are considered.


Geophysics ◽  
1967 ◽  
Vol 32 (4) ◽  
pp. 668-677 ◽  
Author(s):  
Douglas P. O’Brien ◽  
H. F. Morrison

From Maxwell’s equations and Ohm’s law for a horizontally anisotropic medium, it may be shown that two independent plane wave modes propagate perpendicular to the plane of the anisotropy. Boundary conditions at the interfaces in an n‐layered model permit the calculation, through successive matrix multiplications, of the fields at the surface in terms of the fields propagated into the basal infinite half space. Specifying the magnetic field at the surface allows the calculation of the resultant electric fields, and the calculation of the entries of a tensor impedance relationship. These calculations have been programmed for the digital computer and an interpretation of impedances obtained from field measurements may thus be made in terms of the anisotropic layering. In addition, apparent resistivities in orthogonal directions have been calculated for specific models and compared to experimental data. It is apparent that the large scatter of observed resistivities can be caused by small changes in the polarization of the magnetic field.


2006 ◽  
Vol 14 (4) ◽  
Author(s):  
O. Buluy ◽  
Y. Reznikov ◽  
K. Slyusarenko ◽  
M. Nobili ◽  
V. Reshetnyak

AbstractWe describe the experiments on a magnetically-induced drift of the easy axis on a soft surface of photoaligning material fluoro-polyvinyl-cinnamate. We found unexpected partial relaxation of the drift of the easy axis after switching the magnetic field off. This relaxation cannot be explained in a framework of the existing models and requires additional assumptions about the drift process. We propose a model that explains the experimental data suggesting elastic-like behaviour of the polymer fragments during the drift of the easy axis.


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