ISO 18437-1-2012 pdf free download

ISO 18437-1-2012 pdf free download.Mechanical vibration and shock — Characterization of the dynamic mechanical properties of viscoelastic materials — Part 1:Principles and guidelines
Vibrations et chocs mécaniques — Caractérisation des propriétés
mécaniques dynamiques des matérlaux visco-élastiques — Partie 1: Principes et lignes directrices.
4.3.3 Test specimen preparation and mounting
Test specimens are typically cut from a sheet moulded or cast to the desired thickness using a small band saw or razor. It has been found that machining specimens from a thicker sample often affects the properties of the materi&, A typical specimen has length. 1 . (12 t 0,5) mm by width, h (10 ± 0,5) mm by height, h (3 t 0.25) mm. Steel or aluminium end blocks are attached to the ends of the specimen for clamping purposes. The dimensions of the end block are typically I (6,4 ± 0.2) mm by b — (11,0 ± 0,2) mm by ii (4,0 ± 0,2) mm. The specimen is bonded to the end blocks using a rigid adhesive such as epoxy, urethane or cyanoacrylate. The specimen is mounted in a clamping fixture so as to produce the deformation shown in Figure 2.
4.3.4 Data acquisition
First, determine the complex stiffness of the system suspension by making measurements with no specimen in place, Measurements are made both with and without an end block (which serves as an added mass) at low and high frequencies, typically 1 Hz and 30 Hz. Once the stiffness of the instrument has been determined, measurements are made on the specimen mounted as shown in Figure 2. Force is applied to the specimen at the discrete frequencies, typically 0,3 Hz to 30 Hz. and temperatures selected for the evaluation. Typically the maximum displacement is limited to 64 pm.
4.3.5 Analysis of results
The basic principle of operation of the cantilever shear beam apparatus is to determine the force needed to induce a measurable displacement of the specimen. As the magnitude of the displacement depends on the modulus of the specimen, this value may be calculated by relating force to displacement with an equation which involves such factors as the system stiffness and viscous damping coefficient, vibrating mass, specimen geometry, and Poisson ratio. The solution of the dynamic equation yields the elastic Young modulus and loss factor, Details are given in ISO 18437-3.
4.4 Dynamic stiffness method
4.4.1 IntroductIon
The dynamic stiffness of the specimen is determined by measuring the input force on one side of the specimen while the displacement. velocity or acceleration is measured on the same or other side of the specimen, depending on the setup.ISO 18437-1-2012 pdf free download.