The basic problem in teaching mechanics of materials is that some subjects discussed in the reference books are not easy to understand for most of the students. Using experience of many years teaching mechanics of mat...The basic problem in teaching mechanics of materials is that some subjects discussed in the reference books are not easy to understand for most of the students. Using experience of many years teaching mechanics of materials, we have been continuously trying to find easier methods to help the students get a better understanding of fundamental concepts. This effort and investigation has led to innovative and simple approaches to prove the equations much easier than the existing ones and also to clarify complicated concept. In this paper, we are offering our innovative proof for elastic flexure formulas as well as an interesting model for the moment sign convention in the cross section of a beam. In this method, considering a portion of a beam under pure bending and obtaining the stress distribution in the cross section and applying the balance of the considered portion, we prove the Elastic Flexure Formulas much easier than the existing methods. Emphasizing on deeper understanding, some notes and a new model are offered during this proof.展开更多
A new model,called object model,for the simulation of cold roll-forming of tubes is presented.The model inherits the advantages of old models and is the embodiment of forming process that the strip is rolled step by s...A new model,called object model,for the simulation of cold roll-forming of tubes is presented.The model inherits the advantages of old models and is the embodiment of forming process that the strip is rolled step by step from feed rollers to last rolling pass.The elastic-plastic large deformation spline finite strip method based on updated Lagrangian method has been developed by improving the stiffness and transition matrix.Combined theory formulas and new analytical model,the forming process of a tube has been simulated successfully as an example.The analytical results are submitted and indicate that the proposed simulation method and new model are applicable.展开更多
文摘The basic problem in teaching mechanics of materials is that some subjects discussed in the reference books are not easy to understand for most of the students. Using experience of many years teaching mechanics of materials, we have been continuously trying to find easier methods to help the students get a better understanding of fundamental concepts. This effort and investigation has led to innovative and simple approaches to prove the equations much easier than the existing ones and also to clarify complicated concept. In this paper, we are offering our innovative proof for elastic flexure formulas as well as an interesting model for the moment sign convention in the cross section of a beam. In this method, considering a portion of a beam under pure bending and obtaining the stress distribution in the cross section and applying the balance of the considered portion, we prove the Elastic Flexure Formulas much easier than the existing methods. Emphasizing on deeper understanding, some notes and a new model are offered during this proof.
基金the National Natural Science Foundation of China (No. 50375135)the Talent Foundation of Beijing Jiaotong University (No. 2003RC059)
文摘A new model,called object model,for the simulation of cold roll-forming of tubes is presented.The model inherits the advantages of old models and is the embodiment of forming process that the strip is rolled step by step from feed rollers to last rolling pass.The elastic-plastic large deformation spline finite strip method based on updated Lagrangian method has been developed by improving the stiffness and transition matrix.Combined theory formulas and new analytical model,the forming process of a tube has been simulated successfully as an example.The analytical results are submitted and indicate that the proposed simulation method and new model are applicable.
