Papers by Author: Bo Zhou

Abstract: The modified pomelo peel powder was prepared by using chemical modification methods of ZnCl₂ soaking and heating.The removal rate of Pb (II) ion in simulation of wastewater by the modified pomelo peel powder was tested. The effects of pH of wastewater, initial concentrations of Pb (II) ion, adsorbent dosage,temperature and time on adsorption of Pb (II) ion was studied. Results show that when Pb (II) ion initial concentration at 100 mgL^-1, pH of wastewater at 3.5-5.5, adsorption time at 100min, adsorbent dosage at 15gL^-1, temperature at 35°C, the removal rate of Pb (II) ion in simulation of wastewater by the modified pomelo peel powder was more than 95%.

Abstract: The modified corncobs was prepared by using citric acid. Conditions of preparation, the effects of pH, initial concentrations of Cr (VI) and adsorption time to adsorption of Cr (VI) was studied. Results show that when citric acid concentration at 3molL^-1, heating treatment temperature at 160°C, the treatment time at 2h, the modified corncobs had a high adsorption of Cr (VI). At room temperature, Cr (VI) initial concentration at 10 mgL^-1, medium aqueous solution pH at 2.5, adsorption time at 150min, the absorption rate of modified corncobs for Cr (VI) was 96.13%, higher than absorption rate of ordinary corncobs for 22.83%.

Abstract: This paper focuses on the thermo-mechanical behaviors of shape memory alloy (SMA) board with a crack subjected to bending load. The stress field near the crack tip of SMA board is described according to the solution of linear elastic mechanics. The phase transformation behaviors of SMA board are formulated based on Zhou’s one-dimensional phase transformation model. The phase transformation zone equation is derived to describe the phase transformation zone near the crack tip.

Abstract: This paper focuses on the thermo-mechanical behaviors of a shape memory alloy (SMA) plate with a circular hole under biaxial uneven tension. The phase transformation behaviors of SMA under complex stress state are formulated based on the one-dimensional phase transformation model developed by Zhou and Yoon. The stress field equation of the SMA plate with a circular hole is derived according to linear elastic mechanics. The phase transformation behaviors near the region around the circular hole are numerically simulated under different conditions of applied stress.

Abstract: This paper focuses on the thermo-mechanical behaviors of a shape memory alloy (SMA) plate with a crack of mode I. A phase transformation equation is supposed to express the phase transformation behaviors of SMA under complex stress state. The stress field near the crack tip is described based on linear elastic mechanics. The martensitic phase transformation zones near the crack tip at various temperatures are numerically determined.

Abstract: In this paper, the phase transformation behaviors of shape memory alloy (SMA) in the complex stress state are formulated based the one-dimensional phase transformation model supposed by Zhou and Yoon. The stress field near the crack tip of mode II in SMA is described based on linear elastic fracture mechanics. The phase transformation behaviors of SMA near the crack tip of Mode II are numerically investigated.

Abstract: Shape memory alloy (SMA) reinforced composites have been widely used in aerospace engineering fields. In this paper, four basic assumptions were presented to simply the research model based on the Eshelby’s equivalent inclusion method and Mori-Tanaka scheme. Based on the three-phase equivalent system and two-step equivalent process, the effective elastic modulus and thermal expansion coefficient of unidirectional random distribution short SMA fiber reinforced composites were derived. The tensile mechanical properties of composites with fiber volume fraction (15%), size (L=3, D=1; L=5, D=1), and number (N= 30, 50), were simulated using software ANSYS12.0, and discussed the failure mode of the composites.

Abstract: This paper focuses on the modeling of the cyclic super-elastic behaviors of SMA. Cyclic tensile experiments are performed on the NiTi SMA to test its cyclic super-elastic behaviors. A material parameter evolution equation is supposed to express the cyclic effects on the material parameters of the SMA. A cyclic constitutive equation is developed to describe the stress-strain relationship of the SMA under cyclic load. Numerical results show that the cyclic constitutive model, which includes the material parameter evolution equation and cyclic constitutive equation, well predicts the super-elastic behaviors of the SMA subjected to cyclic load.

Abstract: The influence of strain rate on mechanical properties of Ni-Ti SMA wires was investigated by a series of uniaxial loading tests. The influence of strain rate on critical stress was discussed. During the transformation process, the slop of the stress-strain curves was increasing with the increase of strain rate. A new equation was developed to describe the change of residual train based on the test results.

Abstract: DSC test is carried out to determine the phase transformation temperatures of a NiTi SMA, which include martensitic starting temperature, martensitic finishing temperature, austenitic starting temperature and austenitic finishing temperature. The mechanical behaviors of shape memory alloy (SMA) torsion rod are investigated by using Zhou’s shear constitutive equation of SMA and the theorem of circular shaft in mechanics of materials. A critical torque equation is developed to describe the relationship between the martensitic phase transformation critical torque of SMA torsion rod and temperature.