Glass rods have commonly been tested in flexure often due to
their low cost and convenience.ASTM International has a standard
for flexure strength of glass rods, C158 [14], that was originally
prepared in 1940. Fixed loading points of approximately 3 mm radius
are prescribed, but a cautionary note about high contact
stresses is included. The support edges may have a curvature of
approximately 76 mm in the plane of the bearing edge to aid alignment
of the specimens, as shown in Fig. 2. The specimen size is
optional although the minimum diameter must be 4.76 mm
3/16 in.. The length to diameter ratio has to be 10 or greater. El-Weibull [15] cited porcelain rod strengths to support his statistical
model. Porcelain specimens of length 155–178 mm 6 in.–7 in.
with 25 mm 1 in. diameter were common and were usually
loaded in three-point mode on a 127 mm 5 in. outer span. This
configuration was listed as one of many “tentative test methods” in
a fascinating 1928 topical issue of the Journal of the American Ceramic
Society [16]. Very few details of the fixturing were given in
the early papers, but fixed knife edges were the norm. An ASTM
International standard for whitewares, C674 [17], has large specimens
suitable for whitewares and was originally prepared in 1971
to replace two earlier standards. It includes an option for testing
153 mm±13 mm 6 in.±0.5 in. long cylindrical rods of diameters
6.4 mm 1/4 in. to 28.6 mm 1.125 in.. Fixtures with fixed knife
edges located 127 mm 5 in. apart or 76 mm 3 in. for the
6.4 mm diameter rods are specified.
Many advanced or technical ceramics
Glass rods have commonly been tested in flexure often due totheir low cost and convenience.ASTM International has a standardfor flexure strength of glass rods, C158 [14], that was originallyprepared in 1940. Fixed loading points of approximately 3 mm radiusare prescribed, but a cautionary note about high contactstresses is included. The support edges may have a curvature ofapproximately 76 mm in the plane of the bearing edge to aid alignmentof the specimens, as shown in Fig. 2. The specimen size isoptional although the minimum diameter must be 4.76 mm3/16 in.. The length to diameter ratio has to be 10 or greater. El-Weibull [15] cited porcelain rod strengths to support his statisticalmodel. Porcelain specimens of length 155–178 mm 6 in.–7 in.with 25 mm 1 in. diameter were common and were usuallyloaded in three-point mode on a 127 mm 5 in. outer span. Thisconfiguration was listed as one of many “tentative test methods” ina fascinating 1928 topical issue of the Journal of the American CeramicSociety [16]. Very few details of the fixturing were given inthe early papers, but fixed knife edges were the norm. An ASTMInternational standard for whitewares, C674 [17], has large specimenssuitable for whitewares and was originally prepared in 1971to replace two earlier standards. It includes an option for testing153 mm±13 mm 6 in.±0.5 in. long cylindrical rods of diameters6.4 มม. 1/4 มาเพื่อ 28.6 มม. 1.125 ในเข้ามา ส่วนควบ ด้วยมีดถาวรขอบอยู่ 127 มม.ค่ะห่างกัน 5 หรือ 76 มม. 3 ค่ะสำหรับการระบุก้านเส้นผ่าศูนย์กลาง 6.4 มม.เซรามิกส์ขั้นสูง หรือเทคนิคใน
การแปล กรุณารอสักครู่..
