EN 843-2-2006 pdf download.Advanced technical ceramics – Mechanical properties of monolithic ceramics at room temperature – Part 2: Determination of Young’s modulus, shear modulus and Poisson’s ratio.
NOTE 2 If the availability of test material allows, a span of at least 100 mm is recommended to obtain large displacements and to ensure that the compliance of the machine is a small correction if displacement is recorded as a machine cross-head movement.
The test jig shall be for four-point flexure, if displacement is determined by strain gauges or differential transducer,
4.2.2 Test machine
capable of applying a force to the test jig at a constant displacement rate. The test machine shall be equipped for recording the load applied to the test jig at any point in time. The accuracy of the test machine shall be in accordance with EN ISO 7500-1. Grade 1 (1 % of indicated load), and shall be capable of recording to a sensitivity of ≤ 0,1 % of the maximum load employed. The calibration shall have been checked within the previous year.
4.2.3 Displacement or strain measuring device
4.2.3.1 General
Equipment shall be installed to measure the displacement or strain of the loaded test piece by one of three
methods, in accordance with 4.2.3,2, 4.2.3.3 or 4.2.3.4.
4.2.3.2 Method A.1
A facility is designed to measure the apparent displacements of the test machine with the test piece (Figure 1 a)), and with the test piece replaced by a steel or ceramic bar at least 15 mm thick. The difference between these displacements is equivalent to the dispLacement of the test piece in the test jig. The displacement recording device shall be calibrated by comparing machine cross-head displacement with the movement indicated on a dial gauge or other displacement measuring device (see 4.2.5) contacting the cross-head.
4.2.3.3 Method A.2
A facility is designed to measure the displacement of the test piece directly using transducers contacting two defined points on the surface of the test piece between the support loading rollers in three-point or four-point bending (Figure 1 b)). The defined points shall be the centre of the span and one or both loading rollers in four- point bending, or the centre of the span and one or both support rollers in three-point bending. The transducer shall be capable of detecting movements with an accuracy of 0.001 mm, shall have output linear to 0.01 % and shall be calibrated to an accuracy of 0,1 %.
4.2.3.4 Method A.3
A facility is designed to record the strain on the surface of the test piece by using a strain gauge placed on the surface of the test piece between the central loading rollers in four-point bending (Figure 1 C)). The strain gauge and its associated bridge circuit shall have an accuracy of better than 0,1 % and shall be capable of resolving a strain of less than 10.
NOTE 2 If the availability of test material allows, a span of at least 100 mm is recommended to obtain large displacements and to ensure that the compliance of the machine is a small correction if displacement is recorded as a machine cross-head movement.
The test jig shall be for four-point flexure, if displacement is determined by strain gauges or differential transducer,
4.2.2 Test machine
capable of applying a force to the test jig at a constant displacement rate. The test machine shall be equipped for recording the load applied to the test jig at any point in time. The accuracy of the test machine shall be in accordance with EN ISO 7500-1. Grade 1 (1 % of indicated load), and shall be capable of recording to a sensitivity of ≤ 0,1 % of the maximum load employed. The calibration shall have been checked within the previous year.
4.2.3 Displacement or strain measuring device
4.2.3.1 General
Equipment shall be installed to measure the displacement or strain of the loaded test piece by one of three
methods, in accordance with 4.2.3,2, 4.2.3.3 or 4.2.3.4.
4.2.3.2 Method A.1
A facility is designed to measure the apparent displacements of the test machine with the test piece (Figure 1 a)), and with the test piece replaced by a steel or ceramic bar at least 15 mm thick. The difference between these displacements is equivalent to the dispLacement of the test piece in the test jig. The displacement recording device shall be calibrated by comparing machine cross-head displacement with the movement indicated on a dial gauge or other displacement measuring device (see 4.2.5) contacting the cross-head.
4.2.3.3 Method A.2
A facility is designed to measure the displacement of the test piece directly using transducers contacting two defined points on the surface of the test piece between the support loading rollers in three-point or four-point bending (Figure 1 b)). The defined points shall be the centre of the span and one or both loading rollers in four- point bending, or the centre of the span and one or both support rollers in three-point bending. The transducer shall be capable of detecting movements with an accuracy of 0.001 mm, shall have output linear to 0.01 % and shall be calibrated to an accuracy of 0,1 %.
4.2.3.4 Method A.3
A facility is designed to record the strain on the surface of the test piece by using a strain gauge placed on the surface of the test piece between the central loading rollers in four-point bending (Figure 1 C)). EN 843-2-2006 pdf download.