Abstract This work presents an alternative to studying and determining the torsion modulus, G, in composites. For this purpose, we use a measuring system with a rotation motion sensor coupled with a torsion pendulum that allows for determining the angular position as a function of the time. Then, through an equation derived from mechanical spectroscopy studies that permits the calculation of G’s value, the experiments focus on samples of different quantities of calcium carbonate (CaCO3) in unsaturated polyester resins. The results show that CaCO3 (33.33%W) fillers increase G’s value by 88% compared with unsaturated resin (100%W). Furthermore, there is a density increase of approximately 21% with the addition of CaCO3, considering the same two samples, which makes these composites the most massive. The relationship between G and composite density shows that it is possible to change the amount of CaCO3 to increase torsion resistance values in a controlled way.

Abstract This paper presents an alternative method to measure the torsion modulus, G, for samples of polymers. We constructed a measurement system with a force sensor (FS) and a rotational movement sensor (RMS) to obtain a relationship between force (F) and torsion angle (θ). An expression that could return the value of G was deduced using the deformation energy method. This technique is nondestructive and independent of knowing the value of Poisson’s ratio. Samples with different diameters of polytetrafluoroethylene (PTFE) were submitted to quasi-static torsion at the same aspect ratio. The aim was to present and validate the use of the technique for a known polymer. The approximate value of 350 MPa of the torsion modulus G was found for PTFE samples. As the values obtained are within the limits found in the literature, the technique can be used to study samples of polymers and other materials.

Abstract Polyvinylidene fluoride (PVDF) is valued for its properties of transparency to light, lightness, flexibility, mechanical strength, chemical stability, ease of processing, and low-cost production. Ceramics have low mechanical strength and poor processability, but have excellent piezo- and pyroelectric characteristics. The deficiencies of ceramics can be minimized by combining them with polymers. Accordingly, PVDF samples with different percentages of bentonite or LiNbO3 were used to obtain composites via “casting,” and the modulus of elasticity (E) of the composites was studied using a specially designed system. The method used to obtain E took into account the strain energy and the strength of the materials. Based on the results, E decreased with an increased percentage of bentonite and, in the case of LiNbO3, for the percentages of 30% and 35% increases.