ISO 11343:2019 pdf download

ISO 11343:2019 pdf download.Adhesives — Determination of dynamic resistance to cleavage of high-strength adhesive bonds under impact wedge conditions — Wedge impact method
5 Apparatus
5.1 Instrumented impact-testing machine, capable of applying impact energy of at least 50 J and an impact speed of at least 2 m/s. It shall be provided with a suitable grip to hold the specimen. The jaws of this grip shall firmly engage the outer part of the ends of the adherends and shall have provision for positive location of these adherends by means of a hardened-steel bolt passing through the grips and through an 8 mm hole predrilled in the specimens, to clamp the assembly together. For testing, falling-weight and servohydraulic-impact machines may be used as well as pendulum machines. The machine shall be equipped with an instrument capable of registering and storing the force data during the impact event, as a function of time or displacement of the wedge. The response time shall be at least an order of magnitude shorter than the impact event. The machine shall be equipped with a microprocessor/computer in order to perform the necessary calculations for expression of the results. Figure 1 represents a pendulum-type impact machine, using a piezoelectric transducer fixed to the specimen clamp. NOTE Data collection is controlled by the machine type. A servohydraulic machine provides both force-time and force-displacement data, while pendulum-type or falling-weight machines provide only force-time data. Pendulum-type and falling-weight machines do not necessarily allow the calculation of force-displacement data by double integration. Nevertheless, all three machines are usable.
5.2 Test wedge, made of hardened steel, for cleaving the specimen (see Figure 2 and Figure 3, symmetric and asymmetric wedges). The wedge, attached to its support frame which has a vertical degree of freedom, is pulled through the adhesive joint by the force of the impact on the frame. Because of the degree of freedom, the wedge aligns itself with the adhesive joint during the test. The included angle of the wedge, its leading- edge radius and its maximum depth will determine the progression of opening of the bonded joint ahead of the wedge tip. The wedge surface condition and state of cleanliness shall be maintained and inspected before each test, since friction unduly increases the energy consumed. A deformed, bend, scraped, roughened or otherwise compromised wedge shall be replaced and the respective test shall be discarded.