针对金刚石滚轮是一种回转体零件以及其加工制造过程中信息化集成程度低等特点,对金刚石滚轮的特征信息提取、特征加工方案决策、数控程序后置处理等关键技术进行了研究,采用了产品模型数据交换标准STEP AP 242,实现对金刚石滚轮的制造...针对金刚石滚轮是一种回转体零件以及其加工制造过程中信息化集成程度低等特点,对金刚石滚轮的特征信息提取、特征加工方案决策、数控程序后置处理等关键技术进行了研究,采用了产品模型数据交换标准STEP AP 242,实现对金刚石滚轮的制造特征信息提取,使用STEP AP 242和PDM相结合的集成方式,将金刚石滚轮三维模型作为制造加工信息的载体,并选择SolidWorks作为CAD和CAM软件,以及选择Aras Innovator作为PDM平台,使用C#编程语言和数据库技术开发了金刚石滚轮CAD/CAPP/CAM/PDM集成系统,并进行了实例验证。展开更多
The globalization and the intensive competition of th e automotive market require shortening the product development cycle, improving the quality and reducing the cost. Optimizing the product development process, b ui...The globalization and the intensive competition of th e automotive market require shortening the product development cycle, improving the quality and reducing the cost. Optimizing the product development process, b uilding product’s consistent defining model for life cycle, and realizing the in tegration of CAD/CAM/CAE and Concurrent Engineering (CE) become the means to acc ept the challenge. A new product modeling technology, Multi Model Technology (MM T), is provided in this paper to meet the needs of the challenge for automotive powertrain product development. First, the paper introduces the concept of Multi Model Technology. MMT introduce s Object-oriented Technology (OT) into product modeling process and combine OT with feature-based modeling technology. With the help of OT, MMT builds product object model to support system level management in product development. The obj ect model of the product is a Multi Model Structure. The MMS consists of finish part model level (assembly model level), rough part model level (part model leve l), function model level and basic model level. Every models in the MMS is creat ed by feature-based technology in design process. In this case, models in the M MS of product can be shared by casting mould, sand core and sand core mould. The refore, CAD engineers, CAE engineers and CAM engineers can work concurrently and the integration of CAD/CAM/CAE can be realized. Second, MMT is applied in cylinder head development. The multi model structures of cylinder head, its casting mould, sand core and sand core mould are built, an d the process-oriented feature models of every objects in the multi model struc tures are modeled, the application of different model objects in development pro cess is analyzed. The integrated modeling technology of cylinder head, its casti ng mould, sand core and sand core mould under MMT is studied. And the concurrent engineering oriented integration method of CAD/CAE and the method to realize th e integration of CAD/CAE under MMT are also discussed. Based on above, the integ ration of CAD/CAM/CAE of cylinder head is realized in automotive powertrain prod uct. The practice results shows that the modeling technology in this paper can optimi ze the development process, realize the data sharing and concurrent engineering in the product development process.展开更多
【目的】采用CAD/CAM标准测试模型评价四种不同临时冠粘结剂的粘结强度。【方法】参照因牙周病拔除的完整上颌中切牙CAD/CAM40副上颌中切牙的树脂测试模型(包括预备体和带固位孔的临时冠),分为4组(氧化锌组、玻璃离子体水门汀组、磷酸...【目的】采用CAD/CAM标准测试模型评价四种不同临时冠粘结剂的粘结强度。【方法】参照因牙周病拔除的完整上颌中切牙CAD/CAM40副上颌中切牙的树脂测试模型(包括预备体和带固位孔的临时冠),分为4组(氧化锌组、玻璃离子体水门汀组、磷酸锌水门汀组和Tempo Cem NE组),每组10副模型,每组分别采用4种不同的临时冠粘结剂进行粘结。采用MTS力学测试机对每一副模型以1mm/min的速度进行粘结强度测试,测出并记录每组每一副模型的粘结强度。【结果】4组的粘结强度分别为氧化锌组(37.48±4.92)N、玻璃离子体水门汀组(52.13±9.28)N、磷酸锌水门汀组(36.16±6.13)N、Tempo Cem NE组(46.21±6.70)N;玻璃离子体水门汀组和Tempo Cem NE组的粘结强度大于氧化锌组和磷酸锌水门汀组,差异具有统计学意义(P<0.05)。【结论】采用CAD/CAM上颌中切牙的标准测试模型进行4种临时冠粘结剂粘结强度的测试,实验结果认为玻璃离子体水门汀和Tempo Cem NE的粘结效果较好,值得临床广泛应用。展开更多
在软土地区深基坑工程中,选取合适的土体本构模型并确定参数,对基坑开挖中的变形预测及支护结构优化设计尤为重要。为解决软土地区基坑工程中修正剑桥模型参数难以准确获取的问题,提出基于室内试验-贝叶斯理论的建筑基坑软土参数反演方...在软土地区深基坑工程中,选取合适的土体本构模型并确定参数,对基坑开挖中的变形预测及支护结构优化设计尤为重要。为解决软土地区基坑工程中修正剑桥模型参数难以准确获取的问题,提出基于室内试验-贝叶斯理论的建筑基坑软土参数反演方法。首先,通过室内三轴固结不排水试验及标准固结-回弹试验,获取2种土层的修正剑桥模型参数的试验取值及参数反演区间。其次,利用PLAXIS 3D建立基坑有限元模型,运用极差分析法对2种土层的修正剑桥模型参数进行敏感性分析,得出围护结构侧移、地表沉降和坑底隆起对模型参数的敏感性排序。最后,构建基于现场实测数据的贝叶斯反分析框架,利用马尔科夫蒙特卡洛(Markov Chain Monte Carlo,MCMC)算法获取修正剑桥模型参数在不同开挖阶段的后验分布。研究结果表明,贝叶斯反分析方法可用于修正剑桥模型的参数更新,参数更新后的相对误差与其敏感度相关,敏感度越高的参数更新后误差越大。采用更新后的参数计算基坑开挖引起的围护结构水平位移,并与实际监测值进行对比,计算误差相较于利用室内试验参数进行计算的结果显著减小,说明参数更新能提高反分析参数的准确性,验证了贝叶斯反演方法的可靠性和准确性。研究结果可为基坑工程的设计和施工提供理论依据和技术支持。展开更多
文摘针对金刚石滚轮是一种回转体零件以及其加工制造过程中信息化集成程度低等特点,对金刚石滚轮的特征信息提取、特征加工方案决策、数控程序后置处理等关键技术进行了研究,采用了产品模型数据交换标准STEP AP 242,实现对金刚石滚轮的制造特征信息提取,使用STEP AP 242和PDM相结合的集成方式,将金刚石滚轮三维模型作为制造加工信息的载体,并选择SolidWorks作为CAD和CAM软件,以及选择Aras Innovator作为PDM平台,使用C#编程语言和数据库技术开发了金刚石滚轮CAD/CAPP/CAM/PDM集成系统,并进行了实例验证。
文摘The globalization and the intensive competition of th e automotive market require shortening the product development cycle, improving the quality and reducing the cost. Optimizing the product development process, b uilding product’s consistent defining model for life cycle, and realizing the in tegration of CAD/CAM/CAE and Concurrent Engineering (CE) become the means to acc ept the challenge. A new product modeling technology, Multi Model Technology (MM T), is provided in this paper to meet the needs of the challenge for automotive powertrain product development. First, the paper introduces the concept of Multi Model Technology. MMT introduce s Object-oriented Technology (OT) into product modeling process and combine OT with feature-based modeling technology. With the help of OT, MMT builds product object model to support system level management in product development. The obj ect model of the product is a Multi Model Structure. The MMS consists of finish part model level (assembly model level), rough part model level (part model leve l), function model level and basic model level. Every models in the MMS is creat ed by feature-based technology in design process. In this case, models in the M MS of product can be shared by casting mould, sand core and sand core mould. The refore, CAD engineers, CAE engineers and CAM engineers can work concurrently and the integration of CAD/CAM/CAE can be realized. Second, MMT is applied in cylinder head development. The multi model structures of cylinder head, its casting mould, sand core and sand core mould are built, an d the process-oriented feature models of every objects in the multi model struc tures are modeled, the application of different model objects in development pro cess is analyzed. The integrated modeling technology of cylinder head, its casti ng mould, sand core and sand core mould under MMT is studied. And the concurrent engineering oriented integration method of CAD/CAE and the method to realize th e integration of CAD/CAE under MMT are also discussed. Based on above, the integ ration of CAD/CAM/CAE of cylinder head is realized in automotive powertrain prod uct. The practice results shows that the modeling technology in this paper can optimi ze the development process, realize the data sharing and concurrent engineering in the product development process.
文摘【目的】采用CAD/CAM标准测试模型评价四种不同临时冠粘结剂的粘结强度。【方法】参照因牙周病拔除的完整上颌中切牙CAD/CAM40副上颌中切牙的树脂测试模型(包括预备体和带固位孔的临时冠),分为4组(氧化锌组、玻璃离子体水门汀组、磷酸锌水门汀组和Tempo Cem NE组),每组10副模型,每组分别采用4种不同的临时冠粘结剂进行粘结。采用MTS力学测试机对每一副模型以1mm/min的速度进行粘结强度测试,测出并记录每组每一副模型的粘结强度。【结果】4组的粘结强度分别为氧化锌组(37.48±4.92)N、玻璃离子体水门汀组(52.13±9.28)N、磷酸锌水门汀组(36.16±6.13)N、Tempo Cem NE组(46.21±6.70)N;玻璃离子体水门汀组和Tempo Cem NE组的粘结强度大于氧化锌组和磷酸锌水门汀组,差异具有统计学意义(P<0.05)。【结论】采用CAD/CAM上颌中切牙的标准测试模型进行4种临时冠粘结剂粘结强度的测试,实验结果认为玻璃离子体水门汀和Tempo Cem NE的粘结效果较好,值得临床广泛应用。
文摘在软土地区深基坑工程中,选取合适的土体本构模型并确定参数,对基坑开挖中的变形预测及支护结构优化设计尤为重要。为解决软土地区基坑工程中修正剑桥模型参数难以准确获取的问题,提出基于室内试验-贝叶斯理论的建筑基坑软土参数反演方法。首先,通过室内三轴固结不排水试验及标准固结-回弹试验,获取2种土层的修正剑桥模型参数的试验取值及参数反演区间。其次,利用PLAXIS 3D建立基坑有限元模型,运用极差分析法对2种土层的修正剑桥模型参数进行敏感性分析,得出围护结构侧移、地表沉降和坑底隆起对模型参数的敏感性排序。最后,构建基于现场实测数据的贝叶斯反分析框架,利用马尔科夫蒙特卡洛(Markov Chain Monte Carlo,MCMC)算法获取修正剑桥模型参数在不同开挖阶段的后验分布。研究结果表明,贝叶斯反分析方法可用于修正剑桥模型的参数更新,参数更新后的相对误差与其敏感度相关,敏感度越高的参数更新后误差越大。采用更新后的参数计算基坑开挖引起的围护结构水平位移,并与实际监测值进行对比,计算误差相较于利用室内试验参数进行计算的结果显著减小,说明参数更新能提高反分析参数的准确性,验证了贝叶斯反演方法的可靠性和准确性。研究结果可为基坑工程的设计和施工提供理论依据和技术支持。
