Mechanical property measurement flexural modulus

Modulus ma-jo-los npl— i [NL, fr. L, small measure] (1753) (1) A modulus is a measure of a mechanical property of a material, most frequently a stifrhess property. See Flexural Modulus, Shear Modulus,... 

The impact of thermal shock on the properties of a ceramic or a CMC is assessed by means of both destructive and non-destructive testing methods. Flexural or tensile (mainly for CMCs) tests of suitably-sized thermally shocked specimens are usually employed to measure retained mechanical properties as a function of the temperature difference. The temperature differential for which a significant drop in property values is observed is the A A- For monolithic ceramics and particle- or whisker-reinforced CMCs the property under investigation is usually strength, whereas in fibre-reinforced CMCs a drop in Young s modulus is usually a better indication of the onset of damage. 

The Izod notched impact strength (ASTH D-256) and the flexural modulus (ASTM D-790) of the obtained products were measured. For a number of specially selected samples, the dynamic mechanical properties were determined. 

The influence of temperature on basic mechanical properties of the hardened adhesive such as bulk flexural modulus and shear strength is illustrated in Figs. 2.20 and 2.21, respectively (26). From these figures it is evident that the response of all five adhesives to temperature variations within the range 15 " -65 °C is similar. The most noticeable feature of the curves is the rapid deterioration in both stiffness and strength at a temperature close to the measured HDT of the adhesive. 

The development of the WPCs for load-bearing structural applications necessitates the characterization of their strain rate-dependent mechanical properties. In this regard, the effect of strain rate on flexural properties of WPG was addressed by Tamrakar and Lopez [49]. The strain at failure was not significantly influenced by the strain rate variation. A prediction model for the effects on strain rate on the modulus of elasticity (MOE) of WPG material was demonstrated based on the viscoelastic standard solid model. Yu et al. [50] analyzed the variability of the dynamic young s modulus of WPG, which was measured by different non-destructive test (NDT) methods. They also estimated the correlativity between the dynamic Young s modulus and the static MOE of WPG. 

Mechanical properties PTFE maintains its tensile, compressive, and impact properties over a broad temperature range. Hence, it can be used continuously at temperatures up to 260 °C, while still possessing a certain compressive plasticity at temperatures near absolute zero. PTFE is quite flexible and does not break when subjected to stresses of 0.7 MPa according to ASTM D 790. Flexural modulus is about 350-650 MPa at room temperature, about 2000 MPa at —80 °C, and about 45 MPa at 260 °C. The Shore D hardness, measured as per ASTM D 2240, has values between D50 and D60. PTFE exhibits plastic memory, that is, if subjected to tensile or compression stresses below the yield point, part of the resulting deformations remain after the discontinuance of the stresses. If the piece is reheated, the induced strains tend to release themselves within the piece, which resumes its original form. 

Use of anhydride hardeners to crosslink epoxidised oils has received more attention. Boquillon and Fringant [19] studied the kinetics of the polycondensation of epoxidised linseed oil with various aromatic and cycloaliphatic anhydrides at 150-170 °C and characterised the ensuing networks by measuring their Tg and flexural modulus (which both increased with increasing proportion of anhydride) as well as dynamic mechanical properties and their crosslink density. These materials, based partly on renewable resources, displayed adequate properties in terms of applications of thermosets associated with a relatively low Tg (35-110 °C). A similar investigation in which epoxidised vegetable oils substituted with <50% of bisphenol A diglycidyl... 

The mechanical properties of most interest to the PP product design engineer are its stiffness, strength, and impact resistance. Stiffness is measured as the flexural modulus, determined in a flexural test, and impact resistance by a number of different impact tests, with the historical favorite being the Izod impact at ambient and at subambient temperatures. These mechanical properties are mostly used to predict the properties of molded articles. Strength is usually deflned by the stress... 

Besides having an inert material for fibroblastic cells observed at the bone-cement interface, PMMA is still the current standard for cement-held prostheses. Vallo and his group measured the flexural, compressive, and fracture properties of PMMA bone cements that incorporated various amounts of HAp. They found that addition of up to 15 wt% HAp increases the flexural modulus and fracture toughness [89]. It was also observed that, with increasing HAp incorporation into PMMA, the biological responses of the bone cement increased and thus increased osteoblast adhesion and response [88]. Kwon and coworkers reported that a PMMA/HAp composite with 30 wt% of HAp increased the interfacial shear strength at the bone-implant interface 6 weeks after implantation in rabbits [101]. Several other research studies revealed that, depending on the type of bone cement, the addition of HAp can improve the mechanical properties of bone cements [102]. 

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