No abstract

In this paper, a quick stop device technique and the streamline model were employed to study the chip formation in metal cutting. The behavior of chip deformation at the primary shear zone was described by this model. Orthogonal test of turning process over a workpiece of the 6061-T6 aluminum alloy at different cutting speeds was carried out. The results of the equivalent strain rate and cumulative plastic strain were used to describe the complexity of chip formation. Finite element analysis by ABAQUS/explicit package was also employed to verify the streamline model. Some behavior of formation and strain rate distribution differs from the experimental results, but the overall trend and maximum results are approximately close. In addition, the quick stop device technique is described in detail. Which could be used in other kinds of studies, such as the metallurgical observation.

GLARE (glass laminate aluminum-reinforced epoxy) is aluminum-based material of fiber metal laminate (henceforth FML) that is often fabricated by expensive autoclave procedure. In this study, the process of Injected Molding (or also known as VARTM) was employed as a cost-effective alternative to produce GLARE. Several aluminum surface preparation procedures are applied to improve the interlaminar shear strength. A T3 temper 2024 aluminum alloy with 1*1 plain fabricated glass fabrics were used to make GLARE composites. GLARE consists of two aluminum sheet as external layers and glass fabric as internal layers. Four sets of aluminum sheets were prepared, one unanodized and three other anodized. Three different anodizing procedures (constant voltage mode, increasing voltage mode and decreasing voltage mode) have been adopted in this research. Two types of curing treatments were applied on VARTM fabricated specimens. According to ASTM D1876 T-peel test standard, the sets of prepared specimens have been tested to examine the adhesive bonding strength and fracture toughness of mode-I. The obtained results which include forcedisplacement curves, peak loads and fracture toughness were showed that a significant improvement for anodized specimens with all voltage modes. The first curing treatment offered better results than second curing treatment. The best improvement was obtained from anodized specimen with decreasing voltage mode cured by the first treatment which reaches to six times the results obtained from unanodized specimen. The delamination behavior for this specimen was verified numerically.

No abstract

Experimental study of transient response for different load ratio (0.3, 0.4, 0.5, and 1.0)wt% of Multi-Walled Carbon Nano-Tubes (MWCNTs) reinforced matrix of composite in addition to woven carbon fiber. Thermal Low Velocity Impact (TLVI) apparatus have been designed to meet the different testing conditions. The effect of transient vibration by impact loading on simply supported curved composite shell with and without thermal condition has been studied experimentally. An improvement occurred in settling time about 62.0% at increased of weight ratio reinforcement up to 1.0wt% of MWCNTs, and under thermal condition the settling time reduced about 44.0%. The results showed that the material which be selected under thermal condition must be include the weighed ratio 0.4wt% because all the specimens reinforced with the mentioned weighted ratios of MWCNTs failed under thermal test except those that containing 0.4wt% and these results enhanced by other results such as the Differential Scanning Calorimetry (DSC). In addition to the passivity of the composite shell structure due to reinforcement by woven carbon fiber and MWCNTs, active double integral of sliding mode controller (SMC) is used with piezoelectric components. The results indicated that an important improvement in transient response at maximum over shoot of the middle surface point about (95.8%) and (50%) in settling time, with SMC the specimens reach the steady state at short time.