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during high cycle fatigue testing and the tensile behavior of 5A06 aluminum alloy considering the anisotropy were studied.Two types of specimens including longitudinal specimen(parallel to the rolling direction) and transverse specimen(perpendicular to the rolling direction) were prepared.Infrared thermography was employed to monitor the temperature evolution during the fatigue and tensile tests.The......
significantly enhances the compressive stresses, and the net-like γ phase specimen presents a higher value of compressive strain than that of the lamella-like γ phase specimen. Especially, the detwinning plateau of the lamella-like γ phase specimen is almost invisible due to the martensite colonies with low Schmid factors. Finally, according to the calculation of deformation gradient tensor, we found......
. 1 Stress-strain curves of specimen with different sizes at different confining pressures 2.2 试样尺寸对强度特性的影响 图2所示为强风化花岗岩的峰值强度与围压的关系曲线.由图2可见:在同一围压下,尺寸较小试样的峰值强度较大,并且随着围压增加,各试样的峰值强度也逐渐增大,不同试样之间的峰值强度差值也随之增...界状态线 Fig. 4 Critical state lines of strongly weathered granite under different specimen sizes 为进一步探讨试样尺寸对土体临界状态线的影响规律,分别计算3种尺寸试样的临界状态线的斜率M,小尺寸试样的斜率M=1.264,中尺寸试样的斜率M=1.349,大尺寸试样的斜率M=1.350.中尺寸试样与小尺寸试样的斜......
numbers of each section, declined at water-cement ratio of 0.35, increased at 0.45, and changed a little at 0.55. The specimen in the absence of fly ash exhibited less types of hydration products and the surface was observed to be a needle-like ettringite, with a relatively dense overall structure. However, with the increase of fly ash content, pores and micro-cracks of specimen structure increased......
the elastic regime. The results show that the sensitivity increases with the size of specimen increasing and loading rate makes no influence on it. The former is because the deformation of higher specimen is larger than lower one under the same compressive stress. The behind is because the deformation of specimen is the same under the same compressive stress although the loading rate is different......
,and r value of the No.2 specimen hot-rolled in the ferrite region with lubrication are 243 MPa,364 MPa,0.29,and 1.74,respectively,which are similar to those of the No.1 specimen hot-rolled in the conventional austenite region.The elongation rate and bake hardening value of No.2 specimen are 51% and 49.4 MPa,respectively,which are greater than those of No.1 specimen.The No.2 specimen hot-rolled......
, and the characteristics of each fracture mode were identified. The GROD value of the specimen fractured in tension decreases to a constant related to the elongation of corresponding specimen in the far field(farther than 5 mm away from the fracture surface). The peak exhibits in GROD curves of two smooth specimens and a notched specimen near the fracture surface(within 5 mm away from the fracture......
forging on the ductility were investigated in cold upsetting and cup forging. High-temperature annealing was effective to reduce the degree of the texture anisotropy of the specimen, and it was found that the forging limit of the annealed specimen was improved in cold forging. On the other hand, cold cup forging of the annealed specimen was carried out with applying counter pressure. By applying......
) device. Stress states of specimens were monitored with strain gauges on specimen surface and SHPB bars. The failure process of specimen was recorded by ultra speed camera FASTCAM SA1.1 (675 000 fps). Stress histories from strain gauges offer comprehensive information to evaluate the stress equilibrium of specimen in time and space. When a slowly rising load (with loading rates less than 1 200 N/s......
it reaches the critical volume fraction of microvoids,the specimen fractures.During the pure shear test,the stress triaxiality almost equals to zero,and there is almost no microvoids but a shear band... and are later coalesced.When the equivalent plastic strain reaches the critical value(equivalent plastic fracture strain),the butterfly specimen fractures.During the smooth tensile test,the stress triaxiality......