According to the rolling features of plate mill, a 3D elastic-plastic FEM （finite element model） based on full restart method of ANSYS/LS-DYNA was established to study the inhomogeneous plastic deformation of multip...According to the rolling features of plate mill, a 3D elastic-plastic FEM （finite element model） based on full restart method of ANSYS/LS-DYNA was established to study the inhomogeneous plastic deformation of multipass plate rolling. By analyzing the simulation results, the difference of head and tail ends predictive models was found and modified. According to the numerical simulation results of 120 different kinds of conditions, precision plate plan view pattern predictive model was established. Based on these models, the sizing MAS （mizushima automatic plan view pattern control system） method was designed and used on a 2 800 mm plate mill. Comparing the rolled plates with and without PVPP （plan view pattern predictive） model, the reduced width deviation indicates that the olate !olan view Dattern predictive model is preeise.展开更多
The plan view pattern control theoretical models were simplified. Under the condition of constant volume for the plan view pattern compensation, the relation between the thickness and the length can be simplified to t...The plan view pattern control theoretical models were simplified. Under the condition of constant volume for the plan view pattern compensation, the relation between the thickness and the length can be simplified to the linearity in the segment for the plan view pattern control function. The compensation volume can be dispersed for easy calculation. By comparing the model calculation result with the actual result, it was concluded that the simplified model can be used for the online control process.展开更多
Research works on width compensation and correction were carried out in order to eliminate the effects of the PVPC （ plan view pattern control） on width accuracy of plate mill. The thickness correction calculation f...Research works on width compensation and correction were carried out in order to eliminate the effects of the PVPC （ plan view pattern control） on width accuracy of plate mill. The thickness correction calculation formula was derived for compensation the width deviation caused by PVPC function, and the formula is unified under the thinning and thickening conditions. In order to improve the width calculation accuracy, width spread calculation process was modified with dividing one large reduction pass to several small reduction calculation steps. The thickness wedge was simplified to rectangle based on the volume constant principle, and the width spread model for PVPC was constructed. The width compensation and correction for the PVPC functions are used for the online control process, and the Product dimension accuracy is improved. With the decrease of Crop losses, the Droduct yield was increased with 0. 2%.展开更多
The forward slip model with adhesion was used to derive the formula of calculating taper rolling time. The relation between the rolling time and the taper length and the relation between the rolling time and the taper...The forward slip model with adhesion was used to derive the formula of calculating taper rolling time. The relation between the rolling time and the taper length and the relation between the rolling time and the taper thickness can be obtained. The numerical solution for this formula was used on site. According to the simulation result, the roll gap value should be changed linearly with rolling time.展开更多
On the basis of a 5 m plate mill, a 3D rigid-plastic finite element （FE） model was developed to investigate changes of plate plan view patterns during hot rolling process. By analyzing the simulation results of conv...On the basis of a 5 m plate mill, a 3D rigid-plastic finite element （FE） model was developed to investigate changes of plate plan view patterns during hot rolling process. By analyzing the simulation results of conventional rolling processes, it was found that the plate plan view pattern was closely related to broadside rolling ratio. Then, the prediction models for plate plan view patterns were formulated by nonlinear regressive analysis of the simulation results and modified for high accuracy. Based on these models, the broadside compensation rolling method perform- ing at the last pass of broadside rolling phase was designed to decrease plate end crops. Comparing the plate plan view patterns with and without broadside compensation roiling, reduced plate end crops indicate that the broadside compensation roiling model is effective for plate plan view pattern control.展开更多
AIM To analyze planning total hip arthroplasty(THA) with an additional anteroposterior hip view may increases the accuracy of preoperative planning in THA.METHODS We conducted prospective digital planning in 100 conse...AIM To analyze planning total hip arthroplasty(THA) with an additional anteroposterior hip view may increases the accuracy of preoperative planning in THA.METHODS We conducted prospective digital planning in 100 consecutive patients: 50 of these procedures were planned using pelvic overview only(first group), and the other 50 procedures were planned using pelvic overview plus antero-posterior(a.p.) hip view(second group). The planning and the procedure of each patient were performed exclusively by the senior surgeon. Fifty procedures with retrospective analogues planning were used as the control group(group zero). After the procedure, the planning was compared with the eventually implanted components(cup and stem). For statistic analysis the x^2 test was used for nominal variables and the t test was used for a comparison of continuous variables.RESULTS Preoperative planning with an additional a.p. hip view(second group) significantly increased the exact component correlation when compared to pelvic overview only(first group) for both the acetabular cup and the femoral stem(76% cup and 66% stem vs 54% cup and 32% stem). When considering planning ± 1 size, the accuracy in the second group was 96%(48 of 50 patients) for the cup and 94% for the stem(47 of 50patients). In the analogue control group(group zero), an exact correlation was observed in only 1/3 of the cases.CONCLUSION Digital THA planning performed by the operating surgeon and based on additional a.p. hip view significantly increases the correlation between preoperative planning and eventual implant sizes.展开更多
In order to enhance the efficiency of visual inspection and effectively carry out 3D visual coverage tasks,this paper focuses on the 3D view planning problem concerning the visual coverage of an airplane's surface...In order to enhance the efficiency of visual inspection and effectively carry out 3D visual coverage tasks,this paper focuses on the 3D view planning problem concerning the visual coverage of an airplane's surface using unmanned aerial vehicles(UAv).Our objective is to attain a sufficiently high coverage rate with the least number of viewpoints.The contributions of this work are enumerated as follows.Firstly,the 3D model of the target aircraft is spatially extended in accordance with the depth range of the camera mounted on the drone,thereby confining the sampling range of 3D viewpoints.Next,a candidate set of viewpoints is generated through random sampling and the probabilistic potential field technique.Subsequently,we propose a novel hyper-heuristic algorithm.In this algorithm,a genetic algorithm serves as a high-level heuristic strategy,in tandem with multiple low-level heuristic operators devised for combinatorial optimization.This not only augments the capacity to seek the global optimal solution but also expedites the convergence rate,aiming to ascertain the optimal subset of viewpoints.Moreover,we devise a new fitness function for appraising candidate solution vectors in the set covering problem(ScP),strengthening the evolutionary guidance for genetic algorithms.Eventually,experimental findings on the simulated and real airplanes corroborate the efficacy of the proposed method,i.e.,it markedly diminishes the requisite number of viewpoints and augments inspection efficiency.展开更多
基金Item Sponsored by National Science and Technology Support Plan of China (2009AA04Z163)
文摘According to the rolling features of plate mill, a 3D elastic-plastic FEM （finite element model） based on full restart method of ANSYS/LS-DYNA was established to study the inhomogeneous plastic deformation of multipass plate rolling. By analyzing the simulation results, the difference of head and tail ends predictive models was found and modified. According to the numerical simulation results of 120 different kinds of conditions, precision plate plan view pattern predictive model was established. Based on these models, the sizing MAS （mizushima automatic plan view pattern control system） method was designed and used on a 2 800 mm plate mill. Comparing the rolled plates with and without PVPP （plan view pattern predictive） model, the reduced width deviation indicates that the olate !olan view Dattern predictive model is preeise.
基金Item Sponsored by National Economy Trade Committee Foundation(ZZ0113A040201)
文摘The plan view pattern control theoretical models were simplified. Under the condition of constant volume for the plan view pattern compensation, the relation between the thickness and the length can be simplified to the linearity in the segment for the plan view pattern control function. The compensation volume can be dispersed for easy calculation. By comparing the model calculation result with the actual result, it was concluded that the simplified model can be used for the online control process.
基金Sponsored by the Fundamental Research Funds for the Central Universities(Grant No.N120407007)
文摘Research works on width compensation and correction were carried out in order to eliminate the effects of the PVPC （ plan view pattern control） on width accuracy of plate mill. The thickness correction calculation formula was derived for compensation the width deviation caused by PVPC function, and the formula is unified under the thinning and thickening conditions. In order to improve the width calculation accuracy, width spread calculation process was modified with dividing one large reduction pass to several small reduction calculation steps. The thickness wedge was simplified to rectangle based on the volume constant principle, and the width spread model for PVPC was constructed. The width compensation and correction for the PVPC functions are used for the online control process, and the Product dimension accuracy is improved. With the decrease of Crop losses, the Droduct yield was increased with 0. 2%.
基金Item Sponsored by National Economy Trade Committee Foundation (ZZ0113A040201)
文摘The forward slip model with adhesion was used to derive the formula of calculating taper rolling time. The relation between the rolling time and the taper length and the relation between the rolling time and the taper thickness can be obtained. The numerical solution for this formula was used on site. According to the simulation result, the roll gap value should be changed linearly with rolling time.
文摘On the basis of a 5 m plate mill, a 3D rigid-plastic finite element （FE） model was developed to investigate changes of plate plan view patterns during hot rolling process. By analyzing the simulation results of conventional rolling processes, it was found that the plate plan view pattern was closely related to broadside rolling ratio. Then, the prediction models for plate plan view patterns were formulated by nonlinear regressive analysis of the simulation results and modified for high accuracy. Based on these models, the broadside compensation rolling method perform- ing at the last pass of broadside rolling phase was designed to decrease plate end crops. Comparing the plate plan view patterns with and without broadside compensation roiling, reduced plate end crops indicate that the broadside compensation roiling model is effective for plate plan view pattern control.
文摘AIM To analyze planning total hip arthroplasty(THA) with an additional anteroposterior hip view may increases the accuracy of preoperative planning in THA.METHODS We conducted prospective digital planning in 100 consecutive patients: 50 of these procedures were planned using pelvic overview only(first group), and the other 50 procedures were planned using pelvic overview plus antero-posterior(a.p.) hip view(second group). The planning and the procedure of each patient were performed exclusively by the senior surgeon. Fifty procedures with retrospective analogues planning were used as the control group(group zero). After the procedure, the planning was compared with the eventually implanted components(cup and stem). For statistic analysis the x^2 test was used for nominal variables and the t test was used for a comparison of continuous variables.RESULTS Preoperative planning with an additional a.p. hip view(second group) significantly increased the exact component correlation when compared to pelvic overview only(first group) for both the acetabular cup and the femoral stem(76% cup and 66% stem vs 54% cup and 32% stem). When considering planning ± 1 size, the accuracy in the second group was 96%(48 of 50 patients) for the cup and 94% for the stem(47 of 50patients). In the analogue control group(group zero), an exact correlation was observed in only 1/3 of the cases.CONCLUSION Digital THA planning performed by the operating surgeon and based on additional a.p. hip view significantly increases the correlation between preoperative planning and eventual implant sizes.
基金supported by the Trade Union Employee Innovation Foundation of China(2022270024).
文摘In order to enhance the efficiency of visual inspection and effectively carry out 3D visual coverage tasks,this paper focuses on the 3D view planning problem concerning the visual coverage of an airplane's surface using unmanned aerial vehicles(UAv).Our objective is to attain a sufficiently high coverage rate with the least number of viewpoints.The contributions of this work are enumerated as follows.Firstly,the 3D model of the target aircraft is spatially extended in accordance with the depth range of the camera mounted on the drone,thereby confining the sampling range of 3D viewpoints.Next,a candidate set of viewpoints is generated through random sampling and the probabilistic potential field technique.Subsequently,we propose a novel hyper-heuristic algorithm.In this algorithm,a genetic algorithm serves as a high-level heuristic strategy,in tandem with multiple low-level heuristic operators devised for combinatorial optimization.This not only augments the capacity to seek the global optimal solution but also expedites the convergence rate,aiming to ascertain the optimal subset of viewpoints.Moreover,we devise a new fitness function for appraising candidate solution vectors in the set covering problem(ScP),strengthening the evolutionary guidance for genetic algorithms.Eventually,experimental findings on the simulated and real airplanes corroborate the efficacy of the proposed method,i.e.,it markedly diminishes the requisite number of viewpoints and augments inspection efficiency.
