To determine the extrusion force of pipe fabricated by continuous casting and extrusion (CASTEX) using an expansion combination die, the metallic expansion combination die was divided into diversion zone, expansion zo...To determine the extrusion force of pipe fabricated by continuous casting and extrusion (CASTEX) using an expansion combination die, the metallic expansion combination die was divided into diversion zone, expansion zone, flow dividing zone, welding chamber, and sizing zone, and the corresponding stress formulae in various zones were established using the slab method. The deformation zones of CASTEX groove were divided into liquid and semisolid zone, solid primary gripping zone, and solid gripping zone, and the formulae of pipe extrusion forces were established. Experiments were carried out on the self-designed CASTEX machine to obtain the aluminum pipe and measure its extrusion force using the expansion combination die. The experimental results of radial extrusion force for aluminum pipe are in good agreement with the calculated ones.展开更多
As we all know, Immanuel Kant holds the view that human beings are quintessentially rational creatures; hence, the emotions are not much more than a form of excessive psychological baggage that human beings could do w...As we all know, Immanuel Kant holds the view that human beings are quintessentially rational creatures; hence, the emotions are not much more than a form of excessive psychological baggage that human beings could do without. Indeed, for anyone familiar with the television series Star Trek, it would seem that according to Kant human beings bear a quite striking resemblance to the individual known as Spock who is a Vulcan and thus a completely rational creature who does not have emotions and feelings. For Kant, that is how human beings should be when they are at their very best as rational creatures. Interestingly, a question that mightily presents itself is whether or not evolution supports Kant＇s ideal conception of human beings as quintessentially rational creatures. It is quite clear that, unlike Vulcans, human beings are capable of emotions and feelings. Indeed, the capacity for emotions and feelings clearly constitutes a fundamental part of the biological make-up of human beings. With that reality, there are two primary ways we can go. On the one hand, we can hold that notwithstanding the capacity that human beings have for emotions and feelings, it is nonetheless the case that humans should mightily strive to realize the Kantian conception of the rational self. On the other hand, we can hold that the emotions and feelings play a very profound and fundamental role in the survival and self-realization of human beings. In what follows, I shall offer a number of considerations in support of the second line of thought; for in point of fact, the first option is not really an option given the psychological configuration of human beings.展开更多
In this paper,a new dynamic model for the flexible hub-beam system is proposed by using the principle of continuum medium mechanics and the finite element discretization method.In the proposed model,the coupling defor...In this paper,a new dynamic model for the flexible hub-beam system is proposed by using the principle of continuum medium mechanics and the finite element discretization method.In the proposed model,the coupling deformation of any element of the beam is only related with the nodal coordinates of this element.So this model is suitable to the rotating beam in an arbitrary shape.Numerical examples of slender beams in straight and irregular shapes are carried out to demonstrate the validation of the proposed model.Simulation results indicate that the proposed model can be used valid for dynamic description of flexible rotating beam in irregular shape, and for both low and high rotation speeds.展开更多
基金Projects(51334006,50274020)supported by the National Natural Science Foundation of China
文摘To determine the extrusion force of pipe fabricated by continuous casting and extrusion (CASTEX) using an expansion combination die, the metallic expansion combination die was divided into diversion zone, expansion zone, flow dividing zone, welding chamber, and sizing zone, and the corresponding stress formulae in various zones were established using the slab method. The deformation zones of CASTEX groove were divided into liquid and semisolid zone, solid primary gripping zone, and solid gripping zone, and the formulae of pipe extrusion forces were established. Experiments were carried out on the self-designed CASTEX machine to obtain the aluminum pipe and measure its extrusion force using the expansion combination die. The experimental results of radial extrusion force for aluminum pipe are in good agreement with the calculated ones.
文摘As we all know, Immanuel Kant holds the view that human beings are quintessentially rational creatures; hence, the emotions are not much more than a form of excessive psychological baggage that human beings could do without. Indeed, for anyone familiar with the television series Star Trek, it would seem that according to Kant human beings bear a quite striking resemblance to the individual known as Spock who is a Vulcan and thus a completely rational creature who does not have emotions and feelings. For Kant, that is how human beings should be when they are at their very best as rational creatures. Interestingly, a question that mightily presents itself is whether or not evolution supports Kant＇s ideal conception of human beings as quintessentially rational creatures. It is quite clear that, unlike Vulcans, human beings are capable of emotions and feelings. Indeed, the capacity for emotions and feelings clearly constitutes a fundamental part of the biological make-up of human beings. With that reality, there are two primary ways we can go. On the one hand, we can hold that notwithstanding the capacity that human beings have for emotions and feelings, it is nonetheless the case that humans should mightily strive to realize the Kantian conception of the rational self. On the other hand, we can hold that the emotions and feelings play a very profound and fundamental role in the survival and self-realization of human beings. In what follows, I shall offer a number of considerations in support of the second line of thought; for in point of fact, the first option is not really an option given the psychological configuration of human beings.
基金the National Natural Science Foundationof China(Nos.10772113,10772112)
文摘In this paper,a new dynamic model for the flexible hub-beam system is proposed by using the principle of continuum medium mechanics and the finite element discretization method.In the proposed model,the coupling deformation of any element of the beam is only related with the nodal coordinates of this element.So this model is suitable to the rotating beam in an arbitrary shape.Numerical examples of slender beams in straight and irregular shapes are carried out to demonstrate the validation of the proposed model.Simulation results indicate that the proposed model can be used valid for dynamic description of flexible rotating beam in irregular shape, and for both low and high rotation speeds.
