An eight-node solid-beam element based on absolute nodal coordinate formulation(ANCF)which uses cubic interpolation at the longitudinal direction and linear at the transverse direction is proposed.The element can accu...An eight-node solid-beam element based on absolute nodal coordinate formulation(ANCF)which uses cubic interpolation at the longitudinal direction and linear at the transverse direction is proposed.The element can accurately discretize the geometry represented by the Bézier volume with the same basis function order.The continuity property of the proposed beam element is verified.Advantages of the proposed element can be found in the application of leaf spring modeling.The parabolically varying thickness of the leaf can be accurately described.Components in leaf spring such as the spring eye and the rubber bushing can be assembled efficiently since the proposed element can be connected at any direction.The ANCF reference node is used to represent the rigid components and the revolute joints in the vehicle suspension system.Static I-shaped cross-section cantilever beam and flexible pendulum model are used to test the accuracy and dynamic performance of the proposed solid-beam element.The leaf spring model shows the flexibility of the element in modeling the complex mechanical system and the balance between the accuracy and the efficiency.展开更多
As an environmental friendly measure Jbr surface runoff reduction, low impact development （LID） has been applied successfully in urban areas. However, due to high price of land and additional expense for LID constru...As an environmental friendly measure Jbr surface runoff reduction, low impact development （LID） has been applied successfully in urban areas. However, due to high price of land and additional expense for LID construction in highly urbanized areas, the developers of real estate would not like to proceed LID exploitation. Floor area ratio （FAR） refers to ＂the ratio ofa building＇s total floor area to the size of the piece of land upon which it is built.＇＂ Increasing FAR indicates that the developers can construct higher buildings and earn more money. By means of awarding FAR, the developers may be willing to practice LID construction. In this study, a new residential district is selected as a case study to analyze the trade- offbetween the runoffreduction goal achieving by LID practices and the incentive of awarding FAR to promote LID construction. The System for Urban Stormwater Treatment and Analysis IntegratioN （SUSTAIN） model is applied to simulate the runoff reduction under various LID designs and then derive the Pareto-optimal solutions to achieve urban runoff reduction goals based on cost efficiency. The results indicates that the maximum surface runoff reduction is 20.5%. Under the extremity scenarios, the government has options to award FAR of 0.028, 0.038 and 0.047 and the net benefits developers gain are 0 CNY, one million CNY and two million CNY, respectively. The results provide a LID construction guideline related to awarding FAR, which supports incentive policy making for promoting LID practices in the highly urbanized areas.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11802072)Key Project of Science and Technology of Hu'nan Province(Grant No.2018GK1040).
文摘An eight-node solid-beam element based on absolute nodal coordinate formulation(ANCF)which uses cubic interpolation at the longitudinal direction and linear at the transverse direction is proposed.The element can accurately discretize the geometry represented by the Bézier volume with the same basis function order.The continuity property of the proposed beam element is verified.Advantages of the proposed element can be found in the application of leaf spring modeling.The parabolically varying thickness of the leaf can be accurately described.Components in leaf spring such as the spring eye and the rubber bushing can be assembled efficiently since the proposed element can be connected at any direction.The ANCF reference node is used to represent the rigid components and the revolute joints in the vehicle suspension system.Static I-shaped cross-section cantilever beam and flexible pendulum model are used to test the accuracy and dynamic performance of the proposed solid-beam element.The leaf spring model shows the flexibility of the element in modeling the complex mechanical system and the balance between the accuracy and the efficiency.
文摘As an environmental friendly measure Jbr surface runoff reduction, low impact development （LID） has been applied successfully in urban areas. However, due to high price of land and additional expense for LID construction in highly urbanized areas, the developers of real estate would not like to proceed LID exploitation. Floor area ratio （FAR） refers to ＂the ratio ofa building＇s total floor area to the size of the piece of land upon which it is built.＇＂ Increasing FAR indicates that the developers can construct higher buildings and earn more money. By means of awarding FAR, the developers may be willing to practice LID construction. In this study, a new residential district is selected as a case study to analyze the trade- offbetween the runoffreduction goal achieving by LID practices and the incentive of awarding FAR to promote LID construction. The System for Urban Stormwater Treatment and Analysis IntegratioN （SUSTAIN） model is applied to simulate the runoff reduction under various LID designs and then derive the Pareto-optimal solutions to achieve urban runoff reduction goals based on cost efficiency. The results indicates that the maximum surface runoff reduction is 20.5%. Under the extremity scenarios, the government has options to award FAR of 0.028, 0.038 and 0.047 and the net benefits developers gain are 0 CNY, one million CNY and two million CNY, respectively. The results provide a LID construction guideline related to awarding FAR, which supports incentive policy making for promoting LID practices in the highly urbanized areas.
