ASTM D – 00 Structural Panels in Flexure – Download as PDF File .pdf), Text File .txt) or read online. ASTM D – Standard Test Methods for Structural Panels in Flexure. GPa). Wilson and Parasin (26) compared two widths of ply wood ( and mm) using the pure-moment bending test in ASTM D (3).
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D — 00e1 Standard Test Methods for Structural Panels in Flexure1 This standard is issued under the fixed d304 D ; the number immediately following the designation xstm the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last d304. A superscript epsilon e indicates an editorial change since the last revision or reapproval.
However, it may be used to determine the effects of finger d304, veneer joints and gaps, and other features which can be placed entirely between the load points and whose effects can be projected readily to full panel width. Deflection and modulus of elasticity obtained from this method are related to flexural stress only and do not contain a shear component.
Significant errors in modulus of rupture can occur when nominal moment is used see Appendix X1. It is equally well suited for testing uniform or clear material whenever specimen size is adequate. Measured deformation and elastic constants are free of shear deformation effects; and panels can be bent to large deflections without incurring errors from horizontal force components occurring in other methods.
Specimen size and span above certain minimums are quite flexible. It is preferred when equipment is available. Also like Method A, this method asgm small specimens in a center-point simple span test configuration. This method uses asym span to depth ratio, specimen width, test fixture and test speed that make the method d304 suited for quality assurance.
The method is frequently used for quality assurance testing of oriented strand board. These errors are not present in Method C. Structural panels in use include plywood, waferboard, oriented strand board, and composites of veneer asym of wood-based layers. Four methods of tests are included: All methods are applicable to material that is relative uniform in strength and stiffness properties.
Only Method C should be used to test material suspected of having strength or stiffness variations within a panel caused by density variations, knots, knot-holes, areas of distorted grain, fungal attack, or wide growth variations. However, Method B may be used ast evaluate certain features such as core gaps and veneer joints in plywood panels where effects are readily projected to full panels.
Method C generally is preferred where size of test material permits. Moments applied to fail specimens tested by Method A, B or D in which large deflections occur can be considerably larger than nominal. An approximate correction can be made. Total deflection, and modulus of elasticity computed from it, include a relatively constant component attributable to shear deformation.
It is well suited to investigations of many variables that influence properties uniformly throughout the panel in controlled studies and to test small, defect-free control specimens cut from large panels containing defects tested by the large-specimen method.
Current edition approved Apr. Originally published as D — Last previous edition D — It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
To eliminate plate action when wider specimens are tested, the specimen width shall not exceed one third of the span length and precaution shall be taken to ensure uniform bearing across the entire width of the specimen at the load and reaction points.
NOTE 2—In cutting specimens to meet the length requirement, it is not intended that the length be changed for small variations in thickness. Rather, it is intended that the nominal thickness of the material under test should be used for determining the specimen length.
Significance and Use 3. These properties are of primary importance in most structural uses of panels whether in construction for floors, wall sheathing, roof decking, concrete form, or various space plane structures; packaging and materials handling for containers, crates, or pallets; or structural components such as stress-skin panels. Conditioning of test material at controlled atmospheres to control test moisture content and determination of specific gravity are recommended.
Comparisons of results of plywood, veneer composites, and laminates with solid wood or other plywood constructions will be greatly assisted if the thickness of the individual plies is measured to permit computation of section properties.
Measure to the nearest 0. Measure width at mid-span to the nearest 0. NOTE 3—Establishment of a span-depth ratio is required to allow an accurate comparison of test values for materials of different thicknesses. It should be noted that the span is based on the nominal thickness of the material and asrm is not intended that the spans be changed for small variations in thickness. Control of Moisture Asm 4. Design of end supports shall place the center of rotation near the neutral axis of the specimen of average thickness.
Construction is shown in detail in Fig.
ASTM D3043 Flexural Structural Panel Testing Machine
Bearing zstm shall be rounded where they contact the asrm. Construction of a suitable end support using small roller bearings in conjunction with a plate asym clips to the end of the specimen is illustrated in Fig. The use of a large ball bearing to provide lateral compensation for warp is also illustrated. This method is particularly recommended for thin specimens and small loads. For a discussion of these errors, their effects, and methods for reducing them, refer to Appendix X1.
The test proceeds at a constant rate of head motion until either sufficient deflection data in the elastic range have been gathered or until specimen failure occurs. The specimen is supported on reaction bearings which permit the specimen and bearing plate to roll freely over the reactions as the specimen deflects.
The depth of d0343 specimen shall be equal to the thickness of material, and the width shall be 1 in. When the principal direction of the face plies, laminations, strands, or wafers is parallel to the span, the length 2 Annual Book of ASTM Standards, Awtm In cases where excessive local deformation may occur, suitable bearing plates shall be used.
Radius of curvature of bearing plate or block shall not be so large as to cause bridging as the specimen bends. The rate of load application shall be such that the maximum fiber strain rate is equal to 0. Calculate the rate of motion of the movable head as follows: Take deflections by the methods indicated in Fig.
Choose increments of load so that astn less than 12 and preferably 15 or more readings of load and 1 3 D FIG. Similar requirements apply to the load axis. Deflection of mid span relative to two points just inside the load points is measured with a dial gage or transducer thus giving deformation due to pure bending and unaffected by shear deformation.
It may be based on the entire cross section, may include only the moment of inertia of layers parallel to span, or may include all layers weighted in accordance with modulus of elasticity in the direction of bending stress. State clearly the method employed in the report.
D load points plus 48 times specimen thickness or 24 times specimen thickness for the principal direction parallel or perpendicular respectively. Material having high x3043 shear strength or having all its plies, laminations, asm, or wafers parallel to span may use closer spacing between loads and supports.
ASTM D – 17 Standard Test Methods for Structural Panels in Flexure
Other comments as well as those aastm 5. The axes of these surfaces shall d30433 parallel and at least one of them shall be free to turn about its axis or be loaded through rollers to prevent the application of friction forces to astj surface of the specimen.
Construction of a satisfactory loading head is illustrated in Fig. Locate the pivot point that equalizes the two loads near the original neutral axis of the specimen. A spacing of at least 24 and 12 times specimen thickness is awtm for specimens with the principal direction parallel and perpendicular to span respectively. Width shall be 1 in. The alternate width is 12 in. Measurements shall be to the nearest 0. However, it is important that the distance between load point and adjacent support be sufficient to prevent rolling shear failures.
All three points shall lie on the longitudinal axis of the specimen. Suitable equipment of the transducer type is illustrated in Fig. A dial gage could replace the transducer for manual reading.
If individual gage readings are taken, at least 12 and preferably 15 or more load and deflection readings shall be taken below approximate proportional limit or for determining specimen asym. Limitation on size asttm be imposed by equipment size or moment capacity or size of available material.
Except for effects of nonuniformity of properties within a panel, specimen dimensions do not tend to influence test results.
When nonuniform material containing density variation, knots, knot-holes, sloping grain or other sources of large variability is tested for general construction and industrial use, a minimum specimen width d304 24 in. Measure width to the nearest 0. Apply equal and opposite pure moments to each end of the panel by frames.
The frames shall be free to move toward or away from each awtm while under load to preclude application of axtm tension or compression loads at large panel deformations. Support axes of the loading frames to remain in a parallel relationship throughout the test Note 4. Space bars of the loading frames sufficiently to prevent shear failures between where: Method C—Pure Moment Test 7.
Frames atm free to move toward or away from each other during the test to preclude application of other than pure moments to the center span of the panel. Between loading frames deflection of the neutral axis follows a circular arc. Rotational deformation between points near the ends of the arc is measured during the test by special sensing gages resting on pins projecting from the face of the panel at these points.
The test is simple and flexible, and results are directly relatable to basic properties at large deformations. A bar spacing of 20 times panel thickness is suggested to preclude most, if not all, shear failures in the plane of the panel.
In some cases closer spacing may be entirely satisfactory. NOTE 4—These requirements dictate use of specialized equipment which may not be readily available. The principle of a commercially available flexure testing machine complying with these requirements d0343 diagrammed in the figure below.
Until further innovations are made in pure bending test equipment, use of cable and pulley equipment of this type, either purchased or constructed at the laboratory, offers the only practical means of implementing this method. This equipment is the subject of U.