Mechanical testing, three point flexure

Static mechanical properties of aerogels have been measured mainly by the three-point flexure test [54] or by direct longitudinal compression [55]. The... 

The samples were exposed to dry, flowing air at 500°C, 600°C, and 700"C for periods out to 4000 hours. Five samples from each set were retained for as-prepared mechanical evaluation and at least five samples of each set were removed from the furnaces at intervals of 24, 100, 500, 1000, 2000, and 4000 hours. All samples were tested in three-point flexure at room temperature, using an outer loading span of 25.4 mm and a loading rate of 25 MPa/s. 

In this chapter, results from the tensile, flexural and impact tests on HDPE/PA6 and HDPE/PA12 MFC are presented, studying the effects of the compatibilizer, HDPE and PA concentration, as well as the form and arrangement of the reinforcing entities on the mechanical behavior. The UDP MFC laminae were used for tensile tests. Impact strength and three-point flexural tests were performed on the CPC laminates. MRB and NOM composites were analyzed with the three mechanical tests. The data were compared with those of the neat HDPE matrix material and/or the oriented polyamide component [69]. 

Fracture mechanics tests were conducted on an Instron-type displacement controlling test machine (Sanwa Testing Machine Co., Toyohashi, Japan) under a crosshead speed of 0.05 mm/min. All the fracture tests were made in three-point flexural modes. A stable crack extension was observed for all the specimens with the relative notch depth ao/Ws 0.4. However, the crack extension was always unstable for oo/W < 0.4. The apparent fracture toughness, Kq, at the onset of crack initiation for the critical load Pc was determined by... 

ASTM D5023-01 (ISO 6721-3), Standard Test Measuring the Dynamic Mechanical Properties of Plastics in Flexure Using Three Point Bendingf ... 

D5023-01 Standard Test Method for Plastics Dynamic Mechanical Properties In Flexure (Three-Point Bending)... 

As explained previously by Lu et al. [215], there are standard testing methods and equipment that can be employed for reinforced aerogel materiak such as polymer cross-linked ones (X-aerogek), although their standard mechanical characterization does not exist. Flexural tests are carried out in three-point bending mode, normally leading to failure imder tensile bending stresses in... 

Flexural tests according to ASTM D790 were also performed. Rectangular samples wa-e cut from the original molded parts (52.8 x 12.7 x 2.5 mm) and left to relax for 3 weeks before testing. The flexural modulus of the stractural foams was evaluated via a univasal mechanical tester UNITED SFM-10 in the three point bending mode at a velocity of 1 mm/min. A minimum of 5 samples were measured for each condition. 

---