ISO 15108 pdf download.Adhesives — Determination of strength of bonded joints using a bending-shear method
1 Scope
This International Standard describes a procedure for the determination of the strength of adhesive joints, using a bending-shear method. The method can only be used for comparing adhesives, and the results cannot be used for design purposes.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 291 :1 997, Plastics — Standard atmospheres for conditioning and testing . ISO 4587:1 995, Adhesives — Determination of tensile lap-shear strength of rigid-to-rigid bonded assemblies . ISO 4588:1 995, Adhesives — Guidelines for the surface preparation of metals . ISO 5893:1 993, Rubber and plastics test equipment — Tensile, flexural and compression types (constant rate of traverse) — Description . ISO 7500-1 :— 1 ) , Metallic materials — Verification of static uniaxial testing machines — Part 1 : Tensile/compression testing machines . ISO 1 0365:1 992, Adhesives — Designation of main failure patterns . ISO 1 3895:1 996, Adhesives — Guidelines for the surface preparation of plastics .
3 Principle
A bonded lap-joint is loaded in the centre of the bonded area until the joint breaks or until the maximum load is reached. The maximum load recorded is taken as the strength of the assembly.
4 Apparatus
4.1 Tensile-testing machine, operating in the compression mode, capable of maintaining a pre-determined constant crosshead rate. The machine shall be capable of determining a maximum load. The measured strength shall lie between 1 5 % and 85 % of the full-scale capacity of the load-measuring device. The machine shall permit the measurement and recording of the applied force with an accuracy of ± 1 %. The equipment shall be calibrated regularly in accordance with ISO 7500-1 , or in accordance with ISO 5893 in the case of rubber or plastic adherends. NOTE — It is recommended that the machine be autographic, giving a chart that can be read in terms of millimetres of crosshead movement as one coordinate and applied force as the other coordinate. It is also recommended that inertialess equipment be used. 4.2 Supporting base and load-application element, as shown in figure 1 . The load-application element and supporting base shall be made of the same material and have the same radius of curvature at their load-bearing extremities. The contact between the load-application element and the specimen and between the supporting base and the specimen or spacer plate (4.3) shall be uniform over the whole width of the specimen, and the load- application element and supporting base shall be wider than the specimen. 4.3 Spacer plate, as shown in figure 1 , to compensate for the difference in height between the two ends of the specimen due to the overlap of the adherends. The width and thickness of the spacer plate shall be the same as those of the adherends, and the length shall not exceed 1 2,5 mm.
5 Specimens
5.1 Adherend material The adherends shall be made of metal, rigid plastic, rigid fibre-reinforced plastic, wood or wood-based material. 5.2 Shape and dimensions Specimens shall be as shown in figure 2. The adherends shall be of sufficient thickness to ensure breakage of the bond prior to the specimen bottoming out in the fixture. The adherend dimensions, including the thickness, shall be reported in the test report. NOTE — For metal adherends, a thickness of 1 ,6 mm is recommended.5.3 Cleaning and surface treatment of adherends The cleaning and surface treatment of the adherends shall be in accordance with the instructions of the adherend manufacturer and/or adhesive manufacturer, and/or shall be chosen from the methods described in ISO 4588 in the case of metals or ISO 1 3895 in the case of plastics. 5.4 Preparation of specimens Prepare the specimens in accordance with the procedure described in ISO 4587. Apply and cure the adhesive in accordance with the manufacturer’s recommendations. Control the bond line thickness by appropriate means, such as glass spheres or wire spacers. When using glass spheres, the content shall not exceed 0,5 % of the mass of the adhesive. When using wire spacers, prepare the specimens in such a way that the final test piece does not include the area containing the wire. The bond line thickness shall be reported in the test report.