A new linear integration was developed. First, effective strain rate for slab forging with bulge was expressed in terms of two-dimensional strain rate vector, and its inner-product was integrated term by term. Second,...A new linear integration was developed. First, effective strain rate for slab forging with bulge was expressed in terms of two-dimensional strain rate vector, and its inner-product was integrated term by term. Second, a summation process of term by term integrated results and a formula of the bulging were introduced, and an analytical solution of stress effective factor was obtained. It is proved that the expression of power by the above linear integration is the same as that of traditional immediate integration. Also, the solution was simplified by series expansion and compared by slab forging test with the others. It turns out that the calculated result of total forging pressure is basically in agreement with measured value in the actual press test.展开更多
The dual-stream function velocity field is reduced in order to analyze two-dimensional plate broadside roll- ing in roughing. The strain rate vector inner product and integral mean value theorem, as well as coqine vec...The dual-stream function velocity field is reduced in order to analyze two-dimensional plate broadside roll- ing in roughing. The strain rate vector inner product and integral mean value theorem, as well as coqine vector inner product are used respectively in plastic deformation power, friction losses and shear power. A theoretical solution of roll torque and separating force for the rolling is obtained and the calculated results by the solution are compared with those measured in broadside rolling on-line. It shows that both the force and torque calculated are higher than those of measured, but the maximum relative error between them is no more than 11%.展开更多
A new linear integration for plastic power was proposed.The effective strain rate for disk forging with bulge was expressed in terms of two-dimensional strain rate vector,and then its direction cosines were determined...A new linear integration for plastic power was proposed.The effective strain rate for disk forging with bulge was expressed in terms of two-dimensional strain rate vector,and then its direction cosines were determined by the ratio of coordinate increments.Furthermore,inner-product of the vector for plastic power was term integrated by term and summed.Thereafter,through a formula for determination of bulge an analytical solution of stress effective factor was obtained.Finally,through compression tests,the calculated results of above formula were compared with those of Avitzur’s approximate solution and total indicator readings of the testing machine.It is indicated that the calculated compression forces are basically in agreement with the measured ones if the pass reduction is less than 13.35%.However,when the reduction gets up to 25.34% and 33.12%,the corresponding errors between the calculated and measured results also get up to 6% and 13.5%,respectively.展开更多
传统的三维图形处理器通过裁剪操作获取三角形的可见区域。然而,裁剪操作的延迟长且硬件开销高,大量的裁剪操作会降低图形处理器的性能。本文设计了一款基于OpenGL ES 2.0标准的三维图形处理器芯片,采用了统一渲染架构。该图形处理器采...传统的三维图形处理器通过裁剪操作获取三角形的可见区域。然而,裁剪操作的延迟长且硬件开销高,大量的裁剪操作会降低图形处理器的性能。本文设计了一款基于OpenGL ES 2.0标准的三维图形处理器芯片,采用了统一渲染架构。该图形处理器采用高效的无裁剪图形流水线结构,消除了裁剪所带来的硬件开销和性能损耗。此外,本文为该图形处理器设计了一个符合IEEE-754标准的三维向量内积(DP3)计算单元,用于固定功能流水线,以提高图形处理器的性能,并消除图形渲染过程中浮点乘加操作的误差,增强了图形处理器的图形渲染鲁棒性。该三维图形处理器每秒能够处理500 M个顶点和8 G个纹素,功耗为1000 mW,采用了28 nm工艺,面积为7.92 mm^(2)。实现结果表明,与之前的工作相比,本文设计的图形处理器的性能-功耗比提高了27.8%。展开更多
文摘A new linear integration was developed. First, effective strain rate for slab forging with bulge was expressed in terms of two-dimensional strain rate vector, and its inner-product was integrated term by term. Second, a summation process of term by term integrated results and a formula of the bulging were introduced, and an analytical solution of stress effective factor was obtained. It is proved that the expression of power by the above linear integration is the same as that of traditional immediate integration. Also, the solution was simplified by series expansion and compared by slab forging test with the others. It turns out that the calculated result of total forging pressure is basically in agreement with measured value in the actual press test.
基金Sponsored by National Natural Science Foundation of China (51074052,50734002)
文摘The dual-stream function velocity field is reduced in order to analyze two-dimensional plate broadside roll- ing in roughing. The strain rate vector inner product and integral mean value theorem, as well as coqine vector inner product are used respectively in plastic deformation power, friction losses and shear power. A theoretical solution of roll torque and separating force for the rolling is obtained and the calculated results by the solution are compared with those measured in broadside rolling on-line. It shows that both the force and torque calculated are higher than those of measured, but the maximum relative error between them is no more than 11%.
基金Project(50474015) supported by the National Natural Science Foundation of China
文摘A new linear integration for plastic power was proposed.The effective strain rate for disk forging with bulge was expressed in terms of two-dimensional strain rate vector,and then its direction cosines were determined by the ratio of coordinate increments.Furthermore,inner-product of the vector for plastic power was term integrated by term and summed.Thereafter,through a formula for determination of bulge an analytical solution of stress effective factor was obtained.Finally,through compression tests,the calculated results of above formula were compared with those of Avitzur’s approximate solution and total indicator readings of the testing machine.It is indicated that the calculated compression forces are basically in agreement with the measured ones if the pass reduction is less than 13.35%.However,when the reduction gets up to 25.34% and 33.12%,the corresponding errors between the calculated and measured results also get up to 6% and 13.5%,respectively.
