scholarly journals A family of mixed double-Goldberg 6 R linkages

2011 ◽  
Vol 468 (2139) ◽  
pp. 871-890 ◽  
Author(s):  
C. Y. Song ◽  
Y. Chen
Keyword(s):  
Degree Of Freedom ◽  
Construction Process ◽  
Complete Family ◽  
Linkage Method ◽  
The Common ◽  
Overconstrained Linkages

A complete family of double-Goldberg 6 R linkages is reported in this article by combining a subtractive Goldberg 5 R linkage and a Goldberg 5 R linkage through the common link-pair or common Bennett-linkage method. A number of distinct types of overconstrained linkages are built, namely the mixed double-Goldberg 6 R linkages. They all have one degree of freedom and their closure equations are derived in detail. One of them degenerates into a Goldberg 5 R linkage. From the construction process and geometry conditions, the corresponding relationship between the newly found 6 R linkages and the double-Goldberg 6 R linkages, constructed from two Goldberg 5 R linkages or two subtractive Goldberg 5 R linkages, has been established.

scholarly journals The new bud light steel system and the geometric shape evolution of light steel framework for COVID-19 patients appointed hospital (Huoshenshan hospital)

2020 ◽  
Vol 39 (6) ◽  
pp. 9015-9026
Author(s):  
Lilin Wang
Keyword(s):  
Simulation Analysis ◽  
Steel Structure ◽  
Model Material ◽  
Construction Process ◽  
Actual Measurement ◽  
Finite Element Software ◽  
Whole Process ◽  
Long Time ◽  
The Common ◽  
Actual Size

The light steel structure is always the common material of the movable plank house, and the new bud light steel system is the light steel system used for a long time after the earthquake. This paper discusses the mechanical system of the light steel structure of Huoshenshan hospital, which was built in ten days. In the process of building, the geometric form of roof stress has changed. In the actual structural design, the designer seldom takes the calculation of construction load into account, which is quite different from the actual construction process. So it is very important to simulate and monitor the whole process of structure installation. In this paper, the finite element software MIDAS / Gen is used for simulation analysis to ensure that the simulation analysis results are consistent with the construction process, the model material and the actual size are completely consistent, and the stress simulated by the software can meet the needs of the actual stress through the actual measurement.

scholarly journals Compact Laser Collimation System for Simultaneous Measurement of Five-Degree-of-Freedom Motion Errors

2020 ◽  
Vol 10 (15) ◽  
pp. 5057
Author(s):  
Chuang Sun ◽  
Sheng Cai ◽  
Yusheng Liu ◽  
Yanfeng Qiao
Keyword(s):  
Simultaneous Measurement ◽  
Measurement Accuracy ◽  
Measurement Data ◽  
Optical Path ◽  
Degree Of Freedom ◽  
Experimental Setup ◽  
Collimation System ◽  
Optical Configuration ◽  
Series Of Experiments ◽  
The Common

A compact laser collimation system is presented for the simultaneous measurement of five-degree-of-freedom motion errors. The optical configuration of the proposed system is designed, and the principle of the measurement of five-degree-of-freedom errors is described in detail. The resolution of the roll and the horizontal straightness is doubled compared with other laser collimation methods. A common optical path compensation method is provided to detect light drift in real time and compensate for straightness and angle errors. An experimental setup is constructed, and a series of experiments are performed to verify the feasibility and stability of the system. Compared with commercial instruments, the pitch and yaw residuals are ± 2.5 ″ and ± 3.5 ″ without correction, and the residuals are ± 1.9 ″ and ± 2.8 ″ after correction, respectively. The comparison deviations of the horizontal straightness and vertical straightness changed from ± 4.8   μ m to ± 2.8 μm and ± 5.9 μm to ± 3.6 μm, respectively. The comparison deviation of the roll is ± 4.3 ″ . The experimental results show that the data of the five-degree-of-freedom measurement system obtained are largely the same as the measurement data of commercial instruments. The common optical path compensation can effectively improve the measurement accuracy of the system.

scholarly journals Application of Irregular Flowing Water Construction in Architectural Garden Project Management

2018 ◽  
Vol 175 ◽  
pp. 04017
Author(s):  
Li Xiuyun
Keyword(s):  
Project Management ◽  
Virtual Work ◽  
Flowing Water ◽  
Construction Process ◽  
The Common ◽  
General Method

Irregular flowing water construction is the common way of the construction of the garden project. On the basis of elaborating the form of flow water construction, the paper focuses on the general method of irregular flowing water construction, especially in the calculation of activity-on-arrow network, the garden project also needs to be introduced in the form of virtual work, in order to achieve the clear logic of the construction process and continuous construction.

Applied Research of BIM Technology on Prestressed Steel Structures in Xuzhou Stadium

2013 ◽  
Vol 444-445 ◽  
pp. 971-975
Author(s):  
Zhan Sheng Liu ◽  
Xiao Feng Wu ◽  
Rui Long Xu
Keyword(s):  
Construction Industry ◽  
Three Dimensional ◽  
Steel Structure ◽  
Steel Structures ◽  
Space Structure ◽  
Construction Process ◽  
The Family ◽  
The Common ◽  
Three Dimensional Models ◽  
Prestressed Steel Structure

Prestressed steel structure is the common form of space structure. BIM technology is used to every field of the construction industry. In order to apply BIM technology to the design and construction of prestressed steel structures, Xuzhou stadium prestressed structure was took as an example with BIM technology. Firstly, development standards of the family are created. Secondly, three-dimensional positioning technology and then establishing three-dimensional models of BIM are designed. Finally, the construction process of Xuzhou stadium is dynamically simulated.

Influence of Inlet Secondary Curvature on Image-Based CFD Models of the Carotid Bifurcation

2008 ◽  
Author(s):  
Sang-Wook Lee ◽  
David A. Steinman
Keyword(s):  
Carotid Bifurcation ◽  
Velocity Profiles ◽  
Construction Process ◽  
Cfd Modelling ◽  
Measured Velocity ◽  
Cfd Models ◽  
Measured Flow ◽  
The Common ◽  
Made In

In image-based CFD modelling of carotid bifurcation hemodynamics, it is often not possible (or at least not convenient) to impose measured velocity profiles at the common carotid artery (CCA) inlet. Instead, fully-developed velocity profiles are usually imposed based on measured flow rates. Previous work from our group showed that this is reasonable [1], in the sense that errors made in doing so are substantially less than uncertainties inherent in the model construction process itself. In that study, long helical inlet sections were imposed to induce asymmetric (Dean-type) velocity flows profiles consistent with in vivo velocity profiles measured by others at the CCA [2, 3].

Implementation of an Improved Outfit Process Model

2003 ◽  
Vol 19 (01) ◽  
pp. 1-7
Author(s):  
Brian E. Altic ◽  
Richard M. Burns ◽  
B. J. Fontaine ◽  
Ian Scott ◽  
John L. Silveira ◽  
...  
Keyword(s):  
Process Model ◽  
Product Family ◽  
Manufacturing Processes ◽  
Construction Process ◽  
Performance Improvements ◽  
Design And Manufacturing ◽  
New Construction ◽  
The Common ◽  
Pilot Implementation ◽  
Positive Results

National Steel and Shipbuilding Company (NASSCO) has successfully planned and executed several projects directed toward increasing their competitiveness in the shipbuilding marketplace. Among these has been the common goal of implementing outfit design and manufacturing processes that will result in performance improvements. Previous outfit projects, such as MARITECH Ship Factory Transformation Project and Parametric Standard Machinery Units, have focused on key improvement strategies in targeted shipbuilding process areas with positive results. This paper describes the pilot implementation project that was undertaken to establish an onblock and on-board design and construction process. This is a process by which interim product family components are competitively assembled and installed for new construction shipbuilding. Most of the projects completed by NASSCO thus far have been broadly based, focusing on overall development of standard products and processes. This project placed a further focus on these, along with manufacturing processes, workstation definition, production information, and multiskilled tradespeople. These combined elements have been seen as the logical next steps toward process competitiveness.

An Analytical and Experimental Study of Automobile Dynamics With Random Roadway Inputs

1977 ◽  
Vol 99 (4) ◽  
pp. 284-292 ◽  
Author(s):  
A. J. Healey ◽  
E. Nathman ◽  
C. C. Smith
Keyword(s):  
Experimental Study ◽  
Degrees Of Freedom ◽  
Low Frequency ◽  
Vertical Direction ◽  
Degree Of Freedom ◽  
Vehicle Body ◽  
Acceleration Response ◽  
Wide Range ◽  
Frequency Components ◽  
The Common

This paper presents the results of an analytical and experimental study of ride vibrations in an automobile over roads of various degrees of roughness. Roadway roughness inputs were measured. Three different linear mathematical models were employed to predict the acceleration response of the vehicle body. The models used included two, four, and seven degrees of freedom, primarily for vertical direction motion. The results show that the prime source of errors in predicting responses of this type lies in the common assumptions made for roadway roughness spectra. With adequate description of the roadway inputs, the results showed that the seven degree of freedom model accurately predicted the low frequency response (up to 10 Hz). Using the seven degree of freedom model, predicted accelerations compare well with measured data for a wide range of roadways in the low frequency range. Higher frequency components in the measured acceleration response are significant and are illustrated here.

scholarly journals Bioclimatic Architecture

2021 ◽  
Vol 102 ◽  
pp. 03002
Author(s):  
Jimena Ávalos ◽  
Regina Villarreal ◽  
Valeria Cárdenas ◽  
Ana Cristina García-Luna Romero
Keyword(s):  
Climate Change ◽  
Well Being ◽  
Construction Sector ◽  
Construction Process ◽  
New Developments ◽  
Know How ◽  
New Type ◽  
The Common ◽  
The Impact

We are living through serious problems of environmental pollution, which causes great risks to the well-being of the population. These problems are presented by the bad planning of urban growth, and many times in very bad quality. Industrialization grows in the cities without having an order and an appropriate planning to avoid the damage in our environment. The construction sector is largely responsible for this global pollution that is experienced today. As the years go by, architects aim to improve the quality of their construction and improve our quality of life. New projects arise with strategy and planning, developing a new type of architecture which contemplates the damage it would do to the environment and how this issue could be solved based on its construction development. The profession of architects, or urban planners who are involved in the development of cities, are responsible for creating new developments by designing the impact of climate change. The architectural community carries a great responsibility in designing with the flows of materials, energy, climate change, causes and solutions in mind. Architecture must involve sustainability in its construction process and know how to implement it to cause an environmental impact to satisfy the common welfare.

scholarly journals Influence of Higher Modes on Strength and Ductility Demands of Soil–Structure Systems

2016 ◽  
Vol 10 (04) ◽  
pp. 1650006 ◽  
Author(s):  
Behnoud Ganjavi ◽  
Hong Hao ◽  
Iman Hajirasouliha
Keyword(s):  
Soil Structure ◽  
Degree Of Freedom ◽  
Shallow Foundation ◽  
Soil Behavior ◽  
Higher Modes ◽  
Higher Mode Effects ◽  
Lateral Strength ◽  
The Common ◽  
Parametric Analyses ◽  
Strength And Ductility

Due to the inherent complexity, the common approach in analyzing nonlinear response of structures with soil–structure interaction (SSI) in current seismic provisions is based on equivalent Single Degree-of-Freedom systems (E-SDOF). This paper aims to study the influence of higher modes on the seismic response of SSI systems by performing intensive parametric analyses on more than 6400 linear and non-linear Multi Degree-of-Freedom (MDOF) and E-SDOF systems subjected to 21 earthquake records. An established soil-shallow foundation-structure model with equivalent linear soil behavior and nonlinear superstructure has been utilized using the concept of cone models. The lateral strength and ductility demands of MDOF soil–structure systems with different number of stories, structure-to-soil stiffness ratio, aspect ratio and level of inelasticity are compared to those of E-SDOF systems. The results indicate that using the common E-SDOF soil–structure systems for estimating the strength and ductility demands of medium and slender MDOF structures can lead to very un-conservative results when SSI effect is significant. This implies the significance of higher mode effects for soil–structure systems in comparison with fixed-based structures, which is more pronounced for the cases of elastic and low level of inelasticity.

Motion Performance Analysis of Double-Slider Two-DOF Parallel Manipulators

2010 ◽  
Author(s):  
Hong Zhou ◽  
Mukesh Nagapuri ◽  
Sheetal Reddy Mamidi ◽  
Raj Kumar Gandham
Keyword(s):  
Performance Analysis ◽  
Parallel Manipulator ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Serial Manipulators ◽  
Operation Speed ◽  
Transmission Angle ◽  
Motion Performance ◽  
The Common ◽  
Two Degree Of Freedom

Double-slider parallel manipulators are closed-loop two-degree-of-freedom linkages. They are preferred to use because of their simplicity plus the common advantages of parallel manipulators such as high stiffness, load-bearing, operation speed and precision positioning. Like other parallel manipulators, the output motion of double-slider parallel manipulators is not as flexible as two-degree-of-freedom serial manipulators. The motion performance analysis plays a crucial role for this type of parallel manipulator to be applied successfully. In this paper, the linkage feasibility conditions are established based on the transmission angle. When feasibility conditions are satisfied, there is no dead position during operation. The workspace is generated by using curve-enveloping theory. The singularity characteristics are analyzed within the workspace. The motion performance index contours within the workspace are produced using the condition number of the manipulator Jacobian matrix. The results of this paper provide guidelines to design this type of parallel manipulator.

Sign in / Sign up

Export Citation Format

Share Document