提出了一种基于压缩体素模型的锥形刀空间扫描体构造新方法,将锥形刀分解为球体和圆锥体部分,分别给出球体和圆锥体空间扫描体构造公式并构造其表面模型,利用R ay Casting方法分别将球体和圆锥体空间扫描体表面模型进行离散,将其分别转...提出了一种基于压缩体素模型的锥形刀空间扫描体构造新方法,将锥形刀分解为球体和圆锥体部分,分别给出球体和圆锥体空间扫描体构造公式并构造其表面模型,利用R ay Casting方法分别将球体和圆锥体空间扫描体表面模型进行离散,将其分别转化为压缩体素模型,通过布尔并操作生成锥形刀空间扫描体压缩体素模型。该模型采用沿X、Y、Z 3个坐标轴方向相互垂直的D exel模型表示,各个D exel模型之间按体素模型大小均匀分布。刀具空间扫描体模型和仿真工件模型之间的布尔运算转化为D exel模型之间的一维布尔运算,简化了布尔操作并提高了操作速度。通过M arch ing Cubes方法提取数控加工仿真工件表面模型并进行图形显示,提高了显示质量和显示速度,编程人员可从空间任意方向观察和验证仿真结果。该方法在《基于压缩体素模型的五坐标数控加工仿真系统》中得到了应用,克服了现有五坐标数控加工仿真方法和商品化软件系统的不足。展开更多
A prediction model for net cutting specific energy in computer numerical control(CNC)turning based on turning parameters and tool wear is developed.The model can predict the net cutting energy consumption before turni...A prediction model for net cutting specific energy in computer numerical control(CNC)turning based on turning parameters and tool wear is developed.The model can predict the net cutting energy consumption before turning.The prediction accuracy of the model is verified in AISI 1045 steel turning.The comparative experimental results show that the prediction accuracy of the model is significantly improved because the influence of tool wear is taken into account.Finally,the influences of turning parameters and tool wear on net cutting specific energy are studied.With the increase of cutting depth,the net cutting specific energy decreases.With the increase of spindle speed,the additional load loss power of spindle drive system increases,so the net cutting specific energy increases.The net cutting specific energy increases approximately linearly with tool wear.The results are helpful to formulate efficient and energy-saving CNC turning schemes and realize low‑carbon manufacturing.展开更多
Scratch test and friction test were performed to evaluate the internal and external interface behaviors of TiAISiN coating, respectively. The critical compressive and shearing stress of coating failure during scratch ...Scratch test and friction test were performed to evaluate the internal and external interface behaviors of TiAISiN coating, respectively. The critical compressive and shearing stress of coating failure during scratch test were calculated and the values are 30.84 MPa and 4.98 MPa respectively. The average friction coefficients of TiAISiN coat- ing against 2Crl2Ni4Mo3VNbN steel are 0.70 （sliding speed 50 m/rain）, 0.63 （sliding speed 100 m/min）, and 0.81 （sliding speed 150 m/min）. The elements diffusion was analyzed by EDS. A1 and Si element of coating material dif- fuse to the steel disc, except Ti element. The oxidation decreases with the increase of sliding speed, but the adhesion increases with the increase of sliding speed. More A1 element diffuses to the steel disc at the high sliding speed, but the diffusion of Si element keeps almost constant at dlfferent sliding speeds.展开更多
Sustainable development is a holistic approach harmonizing ecological, economical and socio-political needs with respect to the superior objective of enhancing human living standards. Thereby the availability of natur...Sustainable development is a holistic approach harmonizing ecological, economical and socio-political needs with respect to the superior objective of enhancing human living standards. Thereby the availability of natural resources and the conservation of the ecosystems have to be considered that future generations have the possibility to meet their own needs. A long-term economical development demands the transition from a souree-sink economy to a cycle economy as a result of limited resources, limited environmental capacities to absorb waste and emissions as well as increasing needs of a growing population. A reference model for snstainability in manufacturing is presented and used to illustrate sustainable approaches with respect to management, technology, process and product. Adaptation of products and components is a vital element for supporting efficient reuse of products and components. Consequently adaptation contributes to the ambitions goals of snstainability. Technological enablers for adaptation as modularity, information and communication technology are exemplarily introduced. Moreover, approaches for disseminating knowledge in sustainability are given.展开更多
The quality endeavors of an organization, like other enterprise activities, must be oriented towards the economic principles. This approach gives a way to many organizations to question the extent to which the quality...The quality endeavors of an organization, like other enterprise activities, must be oriented towards the economic principles. This approach gives a way to many organizations to question the extent to which the quality management contributes for the overall business success and to pin point the areas where particularly a high value or performance can be created in order to attain the maximum possible economic benefits out of quality management systems. Without including the answer of this question in the decision making process, the resources can not be allocated optimally for the quality purpose. Quality management activities create variety of effects that indirectly contributes towards the economic success and thus increase the company and stakeholder value. A closer look at the quality management philosophy reveals eight major principles namely： customer focus, leadership, involvement of people, process approach, system approach to management, continual improvement, factual approach to decision making, mutually beneficial supplier relationships. These eight principles lead the efforts in the domain of quality management to project a positive impact on the company. For an understanding of response relationships, it is necessary to consider in detail the indicators along the response relationships. They provide helpful clues and give an insight into the complex mechanisms of action of the quality approaches on the path to the company＇s success. The following illustration depicts how the quality based activities generate the value to enhance the performance and a variety of indicators reflects how they indirectly add value to an organization and hence contribute to its economic success.展开更多
文摘提出了一种基于压缩体素模型的锥形刀空间扫描体构造新方法,将锥形刀分解为球体和圆锥体部分,分别给出球体和圆锥体空间扫描体构造公式并构造其表面模型,利用R ay Casting方法分别将球体和圆锥体空间扫描体表面模型进行离散,将其分别转化为压缩体素模型,通过布尔并操作生成锥形刀空间扫描体压缩体素模型。该模型采用沿X、Y、Z 3个坐标轴方向相互垂直的D exel模型表示,各个D exel模型之间按体素模型大小均匀分布。刀具空间扫描体模型和仿真工件模型之间的布尔运算转化为D exel模型之间的一维布尔运算,简化了布尔操作并提高了操作速度。通过M arch ing Cubes方法提取数控加工仿真工件表面模型并进行图形显示,提高了显示质量和显示速度,编程人员可从空间任意方向观察和验证仿真结果。该方法在《基于压缩体素模型的五坐标数控加工仿真系统》中得到了应用,克服了现有五坐标数控加工仿真方法和商品化软件系统的不足。
基金supported by the Project of Shandong Province Natural Science Foundation of China (No. ZR2016EEM29)the Project of Shandong Province Key Research Development of China (No.2017GGX30114)。
文摘A prediction model for net cutting specific energy in computer numerical control(CNC)turning based on turning parameters and tool wear is developed.The model can predict the net cutting energy consumption before turning.The prediction accuracy of the model is verified in AISI 1045 steel turning.The comparative experimental results show that the prediction accuracy of the model is significantly improved because the influence of tool wear is taken into account.Finally,the influences of turning parameters and tool wear on net cutting specific energy are studied.With the increase of cutting depth,the net cutting specific energy decreases.With the increase of spindle speed,the additional load loss power of spindle drive system increases,so the net cutting specific energy increases.The net cutting specific energy increases approximately linearly with tool wear.The results are helpful to formulate efficient and energy-saving CNC turning schemes and realize low‑carbon manufacturing.
基金Supported by China Postdoctoral Science Foundation(No. 20110490380 and No. 20110490383)Dongfang Turbine Co, Ltd (No. 2011GZ011)State Key Laboratory of Tribology, Tsinghua University (No. SKLT10A01)
文摘Scratch test and friction test were performed to evaluate the internal and external interface behaviors of TiAISiN coating, respectively. The critical compressive and shearing stress of coating failure during scratch test were calculated and the values are 30.84 MPa and 4.98 MPa respectively. The average friction coefficients of TiAISiN coat- ing against 2Crl2Ni4Mo3VNbN steel are 0.70 （sliding speed 50 m/rain）, 0.63 （sliding speed 100 m/min）, and 0.81 （sliding speed 150 m/min）. The elements diffusion was analyzed by EDS. A1 and Si element of coating material dif- fuse to the steel disc, except Ti element. The oxidation decreases with the increase of sliding speed, but the adhesion increases with the increase of sliding speed. More A1 element diffuses to the steel disc at the high sliding speed, but the diffusion of Si element keeps almost constant at dlfferent sliding speeds.
文摘Sustainable development is a holistic approach harmonizing ecological, economical and socio-political needs with respect to the superior objective of enhancing human living standards. Thereby the availability of natural resources and the conservation of the ecosystems have to be considered that future generations have the possibility to meet their own needs. A long-term economical development demands the transition from a souree-sink economy to a cycle economy as a result of limited resources, limited environmental capacities to absorb waste and emissions as well as increasing needs of a growing population. A reference model for snstainability in manufacturing is presented and used to illustrate sustainable approaches with respect to management, technology, process and product. Adaptation of products and components is a vital element for supporting efficient reuse of products and components. Consequently adaptation contributes to the ambitions goals of snstainability. Technological enablers for adaptation as modularity, information and communication technology are exemplarily introduced. Moreover, approaches for disseminating knowledge in sustainability are given.
文摘The quality endeavors of an organization, like other enterprise activities, must be oriented towards the economic principles. This approach gives a way to many organizations to question the extent to which the quality management contributes for the overall business success and to pin point the areas where particularly a high value or performance can be created in order to attain the maximum possible economic benefits out of quality management systems. Without including the answer of this question in the decision making process, the resources can not be allocated optimally for the quality purpose. Quality management activities create variety of effects that indirectly contributes towards the economic success and thus increase the company and stakeholder value. A closer look at the quality management philosophy reveals eight major principles namely： customer focus, leadership, involvement of people, process approach, system approach to management, continual improvement, factual approach to decision making, mutually beneficial supplier relationships. These eight principles lead the efforts in the domain of quality management to project a positive impact on the company. For an understanding of response relationships, it is necessary to consider in detail the indicators along the response relationships. They provide helpful clues and give an insight into the complex mechanisms of action of the quality approaches on the path to the company＇s success. The following illustration depicts how the quality based activities generate the value to enhance the performance and a variety of indicators reflects how they indirectly add value to an organization and hence contribute to its economic success.
