ISO 6707-4:2021 pdf – Buildings and civil engineering works – Vocabulary一 Part 4: Facility management terms

ISO 6707-4:2021 pdf – Buildings and civil engineering works – Vocabulary一 Part 4: Facility management terms.
2 Normative reference The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 1183-1, Plastics — Methods for determining the density of non-cellular plastics — Part 1: Immersion method, liquid pycnometer method and titration method ISO 1183-2, Plastics — Methods for determining the density of non-cellular plastics — Part 2: Density gradient column method ISO 1183-3, Plastics — Methods for determining the density of non-cellular plastics — Part 3: Gas pyknometer method ISO 6721-1, Plastics — Determination of dynamic mechanical properties — Part 1: General principles 3? Terms? and? definitions For the purposes of this document, the terms and definitions given in ISO 6721-1 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https://www.iso.org/obp — IEC Electropedia: available at http://www.electropedia.org/ 4 Principle A specimen is submitted to forced bending vibrations in the frequency range between about 10 Hz and 1 000 Hz. The resonance curve (see ISO 6721-1) is determined and, from the curve obtained, the flexural storage modulus E′ f is calculated in the range above 0,5 MPa and the loss factor given by tan δ = E″ f /E′ f is calculated in the range between about 10 −2 and 10 −1 (see NOTE). The test frequency can be varied by making measurements at more than one vibrational order. The measurement range for the flexural loss modulus E″ f is determined by that of the loss factor and by the value of the storage modulus.
6 Test specimens 6.1 General According to ISO 6721-1. 6.2 Shape and dimensions Specimens shall be rectangular bars or strips thick enough to give sufficient bending stiffness, which is critical for the resonance frequency. On the other hand, the thickness shall be sufficiently small when compared to the wavelength of the bending vibration. The specimen thickness shall also be limited to avoid effects due to shear deformation and rotatory inertia if accurate values of E′ are required. Length-to-thickness ratios of less than 50 shall be avoided if values of E′ are required to be accurate to within ±5 %, from measurements up to the sixth order of homogeneous, isotropic specimens. The thickness of the layers of a multilayer system will depend on the purpose for which the system was designed. When comparing various systems by the bending-vibration test, the preferred ratio of the mass of the plastic layer to the mass of the basic sheet material is 1:5. The width of the specimens shall be less than one-half of the wavelength used in order to avoid lateral resonance vibrations. A width of 10 mm should be suitable in most cases. The length of the specimens depends on the desired frequency. For specimens clamped at one end, the length shall be sufficiently large to avoid the clamp influencing the vibration significantly. A free length of 180 mm should be used. If the specimen is not clamped, its length shall be 150 mm. 6.3 Preparation According to ISO 6721-1. Small, thin, light steel plates shall be adhesively bonded to the specimens near their ends to allow excitation and detection of the vibrations by means of electromagnetic transducers. To avoid errors in E′ greater than 4 %, the ratio of the added mass to the specimen mass shall not exceed 1 %. To avoid the steel plates causing additional stiffness, they shall not extend along more than 2 % of the length of the specimen. The distance between the steel plates shall be large enough to avoid cross-talk between exciter and detector.
8 Conditioning According to ISO 6721-1. 9 Procedure 9.1 Test atmosphere According to ISO 6721-1. 9.2 Measurement of specimen cross‑section According to ISO 6721-1. 9.3 Measurement of specimen density Measure the density of the test specimen, ρ (kg m −3 ) to an accuracy of ±0,5 % using one of the procedures described in ISO 1183-1 or ISO 1183-2 or ISO 1183-3. 9.4 Mounting the test specimens and adjustment of the transducers 9.4.1 Method A Clamp the specimen so that the clamping force is high enough to avoid additional damping from friction between the specimen and the clamp (see 5.2). Measure the free length L of the specimen to ±0,5 %.