Introduction

The invention concerns an innovative tool for measuring the shear properties of fiber-reinforced composite materials, in particular according to the ASTM D7078 standard. This standard determines the shear properties of fiber-reinforced composite materials by locking the ends of the V-notch specimens between two pairs of load rails.

The invention being protected allows to solve some problems that affect the correct performance of the test, managing the measurement parameters in an optimal manner.

Technical features

The invention solves some currently existing problems, in terms of friction, temperature, overall dimensions for measuring the shear properties of fibrous composite materials, based on the ASTM D7078 standard, currently considered the “state-of-the-art”. This standard has the function of determining the shear properties of fiber-reinforced composite materials by locking the ends of the V-notch specimens between two pairs of load rails. This is made possible thanks to a low-friction guide system integrated into it and the use of a DIC (Digital Image Correlation) system for the measurement of deformations.

Furthermore, the invention allows to carry out mechanical shear tests, according to the standard, in the whole range of temperatures of engineering interest, for composite materials reinforced with fibers, including those types for which the ISO standard recommends particular attention: fiber composites long unidirectional and fabric-reinforced composites.

Finally, the equipment is more compact and lighter than most of those currently on the market and therefore easier to use in operational situations.

Possible Applications

• Measurement of the shear strength of composite materials for the following areas of use:
  • Aerospace;
  • Aeronautics;
  • Automotive.

Advantages

• Improvement of the accuracy of the measurements of the properties of composite materials;
• Adaptability of the invention to existing industrial equipment;
• High productivity and cost-effectiveness of the equipment at an industrial level.