As one of the oldest creatures on the earth, the tortoises have formed a nearly perfect shell structure after millions of years of evolution In this paper, Chinese tortoise shell is studied. Firstly, the scanni...As one of the oldest creatures on the earth, the tortoises have formed a nearly perfect shell structure after millions of years of evolution In this paper, Chinese tortoise shell is studied. Firstly, the scanning model of the tortoise shell is established by means of computer tomography （CT） scanning technology and MIMICS software. Secondly, the solid model of three-dimensional structure of the tortoise shell is constructed by using geomagic studio reverse engineering software. Afterwards, the compression numerical simulation of the tortoise shell structure under low strain rate is conducted with the help of finite element software LS-DYNA. Finally, load-bearing characteristics of the tortoise shell structure and dome-shaped structure are compared and analyzed. The results show that compared withthe dome-shaped structure with the same volume, tortoise shell structure has a higher structural rigidity and can withstand higher pressure. Therefore, tortoise shell structure provide some reference to the design of armored vehicles, sheltersand other types of thin shell structures.展开更多
In software engineering as in all other engineering fields, the product to be built is divided into sub-parts that are independently constructed and subsequently assembled. This procedure reduces the complexity and im...In software engineering as in all other engineering fields, the product to be built is divided into sub-parts that are independently constructed and subsequently assembled. This procedure reduces the complexity and improves the reuse of the developed products. MDE （model-driven engineering） is a recent initiative that adopts this approach. In this context, model composition has become an important artifact in the MDE domain that allows constructing and composing an efficient assembly process. This paper will attempt to identify the strength and the drawbacks of the existing composition model paradigms, and determine the various parameters that govern their behavior.展开更多
This paper introduces CBFEM （component-based finite element model） which is a new method to analyze and design connections of steel structures. Design focused CM （component model） is compared to FEM （finite eleme...This paper introduces CBFEM （component-based finite element model） which is a new method to analyze and design connections of steel structures. Design focused CM （component model） is compared to FEM （finite elements models）. Procedure for composition of a model based on usual production process is used in CBFEM. Its results are compared to those obtained by component method for portal frame eaves moment connection with good agreement. Design of moment resistant column base is demonstrated by a case loaded by two directional bending moments and normal force. Interaction of several connections in one complex joint is explained in the last example. This paper aims to provide structural engineers with a new tool to effectively analyze and design various joints of steel structures.展开更多
The sustainable design approach presented in this paper supports an increased commitment to environmental stewardship and conservation, and results in an optimal balance of cost, environmental, societal, and human ben...The sustainable design approach presented in this paper supports an increased commitment to environmental stewardship and conservation, and results in an optimal balance of cost, environmental, societal, and human benefits while meeting the mission and function of the intended space structure. The aim of this paper is to develop the guidelines that could be applied in the design of a space structure in order to achieve the optimal overall lifetime performance of the space structure. Space structures are more than inanimate hunks of metal, glass and fabric. Every space structure that we design as structural engineers is like a child - a child that is conceived with a passionate vision of its form, structure and purpose; nurtured through the schematic design phase and the development of construction documents; and cared for during the labor pains of plan check corrections, requests for information, shop drawing review, and construction observation. Like children, our space structures mature, perform necessary functions during their lives, and eventually, grow old and die. The design of a sustainable space structure is a much more challenging and cross-disciplinary process than in the past and therefore it is necessary that the space structure is viewed as an integrated system and that all members of the design team work in a fully integrated fashion.展开更多
The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butt...The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butterfly wings is not only structure-based but also viewing-angle-dependent. Firstly, the discoloration effect of this typical butterfly was confirmed by a series of experiments. Then, the general form, arrangements, and geometrical dimensions of the scales were observed using a stereomicroscope. Scanning electron microscopy was also used to examine the two-dimensional morphologies and structures of a single scale. Afterwards, one model with the optimized three-dimensional profile of the structure was described using Pro-engineer software. The associate model was then analyzed to reconstruct the process between the incident light and the model surface. Finally, the mechanism of the angle-dependent discoloration effect was analyzed by theoretical calculation and optical simulation. Different light propagation paths and the length of the incident light at different angles caused destructive or constructive interference between the light reflected from the different layers. The different spectra of the reflected light make the wings appear with different structural colors, thereby endowing the angle-dependent discoloration effect. The consistency of the calculation and simulation results confirms that these structures possess an excellent angle-dependent discoloration effect. This functional "biomimetic structure" would not only be of great scientific interest but could also have a great impact in a wide range of applications such as reflective displays, credit card security, and military stealth technology.展开更多
文摘As one of the oldest creatures on the earth, the tortoises have formed a nearly perfect shell structure after millions of years of evolution In this paper, Chinese tortoise shell is studied. Firstly, the scanning model of the tortoise shell is established by means of computer tomography （CT） scanning technology and MIMICS software. Secondly, the solid model of three-dimensional structure of the tortoise shell is constructed by using geomagic studio reverse engineering software. Afterwards, the compression numerical simulation of the tortoise shell structure under low strain rate is conducted with the help of finite element software LS-DYNA. Finally, load-bearing characteristics of the tortoise shell structure and dome-shaped structure are compared and analyzed. The results show that compared withthe dome-shaped structure with the same volume, tortoise shell structure has a higher structural rigidity and can withstand higher pressure. Therefore, tortoise shell structure provide some reference to the design of armored vehicles, sheltersand other types of thin shell structures.
文摘In software engineering as in all other engineering fields, the product to be built is divided into sub-parts that are independently constructed and subsequently assembled. This procedure reduces the complexity and improves the reuse of the developed products. MDE （model-driven engineering） is a recent initiative that adopts this approach. In this context, model composition has become an important artifact in the MDE domain that allows constructing and composing an efficient assembly process. This paper will attempt to identify the strength and the drawbacks of the existing composition model paradigms, and determine the various parameters that govern their behavior.
文摘This paper introduces CBFEM （component-based finite element model） which is a new method to analyze and design connections of steel structures. Design focused CM （component model） is compared to FEM （finite elements models）. Procedure for composition of a model based on usual production process is used in CBFEM. Its results are compared to those obtained by component method for portal frame eaves moment connection with good agreement. Design of moment resistant column base is demonstrated by a case loaded by two directional bending moments and normal force. Interaction of several connections in one complex joint is explained in the last example. This paper aims to provide structural engineers with a new tool to effectively analyze and design various joints of steel structures.
文摘The sustainable design approach presented in this paper supports an increased commitment to environmental stewardship and conservation, and results in an optimal balance of cost, environmental, societal, and human benefits while meeting the mission and function of the intended space structure. The aim of this paper is to develop the guidelines that could be applied in the design of a space structure in order to achieve the optimal overall lifetime performance of the space structure. Space structures are more than inanimate hunks of metal, glass and fabric. Every space structure that we design as structural engineers is like a child - a child that is conceived with a passionate vision of its form, structure and purpose; nurtured through the schematic design phase and the development of construction documents; and cared for during the labor pains of plan check corrections, requests for information, shop drawing review, and construction observation. Like children, our space structures mature, perform necessary functions during their lives, and eventually, grow old and die. The design of a sustainable space structure is a much more challenging and cross-disciplinary process than in the past and therefore it is necessary that the space structure is viewed as an integrated system and that all members of the design team work in a fully integrated fashion.
基金supported by the National Natural Science Foundation of China(Grant Nos.51325501,51505183&51290292)China Postdoctoral Science Foundation Funded Project(Project No.2015 M571360)
文摘The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butterfly wings is not only structure-based but also viewing-angle-dependent. Firstly, the discoloration effect of this typical butterfly was confirmed by a series of experiments. Then, the general form, arrangements, and geometrical dimensions of the scales were observed using a stereomicroscope. Scanning electron microscopy was also used to examine the two-dimensional morphologies and structures of a single scale. Afterwards, one model with the optimized three-dimensional profile of the structure was described using Pro-engineer software. The associate model was then analyzed to reconstruct the process between the incident light and the model surface. Finally, the mechanism of the angle-dependent discoloration effect was analyzed by theoretical calculation and optical simulation. Different light propagation paths and the length of the incident light at different angles caused destructive or constructive interference between the light reflected from the different layers. The different spectra of the reflected light make the wings appear with different structural colors, thereby endowing the angle-dependent discoloration effect. The consistency of the calculation and simulation results confirms that these structures possess an excellent angle-dependent discoloration effect. This functional "biomimetic structure" would not only be of great scientific interest but could also have a great impact in a wide range of applications such as reflective displays, credit card security, and military stealth technology.
