Multistage Geared Geneva Mechanism

1979 ◽  
Vol 101 (1) ◽  
pp. 41-46 ◽  
Author(s):  
A. T. Yang ◽  
L. M. Hsia
Keyword(s):  
Kinematic Analysis ◽  
Dwell Time ◽  
Rational Design ◽  
Design Parameters ◽  
Design Concepts ◽  
The Family ◽  
Gear Trains ◽  
N Stage ◽  
Phase Angles ◽  
Fine Tune

Design concepts for an n-stage geared Geneva mechanism, which is an assembly of n Geneva mechanisms connected by (n−1) gear trains, are proposed in this paper. The dwell time produced by the system is a function of (n−1) phase angles, the combined number of slots on all the wheels and the number of pins on all cranks in the system. The introduction of phase angles into the family of design parameters is highly significant: it gives the engineer an added dimension in the design of intermittent mechanisms and it gives him the flexibility to fine-tune their dwell time. For illustrative purposes, the derivation for the dwell time and the kinematic analysis of a two-stage geared Geneva mechanism are treated in detail. It is hoped that the results, which are presented in the form of charts and graphs, would be useful for the rational design of intermittent mechanisms.

Kinematic analysis and deformation of a planar lattice with an arbitrary number of panels

2020 ◽  
pp. 15-19
Author(s):  
M.N. Kirsanov
Keyword(s):  
Exact Solution ◽  
Kinematic Analysis ◽  
Arbitrary Number ◽  
Design Parameters ◽  
Lattice Deformation ◽  
Planar Lattice ◽  
Force Loading

Formulae are obtained for calculating the deformations of a statically determinate lattice under the action of two types of loads in its plane, depending on the number of panels located along one side of the lattice. Two options for fixing the lattice are analyzed. Cases of kinematic variability of the structure are found. The distribution of forces in the rods of the lattice is shown. The dependences of the force loading of some rods on the design parameters are obtained. Keywords: truss, lattice, deformation, exact solution, deflection, induction, Maple system. [email protected]

Experiences with alluvial foundations for earth dams in the Prairie provinces

1979 ◽  
Vol 16 (2) ◽  
pp. 255-271 ◽  
Author(s):  
N. Peters ◽  
K. N. Lamb
Keyword(s):  
Rational Design ◽  
Preliminary Design ◽  
Empirical Relationships ◽  
Design Concepts ◽  
Theoretical Design ◽  
Pore Pressures ◽  
Wide Range ◽  
Thick Layers ◽  
Limited Testing ◽  
Prairie Provinces

The foundations for numerous dams in proglacial and interglacial valleys in the Prairie provinces consist of soft alluvial soils. The deposits are up to 60 m deep, and contain thick layers of clay interspersed with lenses and layers of silt, sand, and gravel.This paper describes the damsite investigation and laboratory testing required, the design methods and construction procedures used, and the foundation performance observed during and after construction. A number of empirical relationships between index tests and physical properties of the soils, which provide useful guidelines for preliminary design, are presented.The design approach has gradually evolved from an empirical design with limited testing to a more rational design based on detailed investigations and thorough instrumentation. Increased reliance is placed on observational apparatus to monitor movements and pore pressures to confirm design assumptions as construction proceeds. The theoretical design is always checked with former designs of dams that have performed satisfactorily.Safe economical dams have been constructed in spite of large deformations and high pore pressures. Two case histories illustrate the wide range in dam design for alluvial foundations. The first shows an older design cross section with modifications required to ensure a stable dam, and the second describes a recently constructed dam that incorporates many of the latest design concepts.

Implementing the Mechanistic–Empirical Design Guide Procedure for a Hot-Mix Asphalt–Rehabilitated Pavement in Indiana

2005 ◽  
Vol 1919 (1) ◽  
pp. 121-133 ◽  
Author(s):  
Khaled A. Galal ◽  
Ghassan R. Chehab
Keyword(s):  
Hot Mix Asphalt ◽  
Pavement Design ◽  
Design Parameters ◽  
Design Procedures ◽  
Design Concepts ◽  
Asphalt Overlay ◽  
Design Guide ◽  
Strategic Goals ◽  
And Performance

One of the Indiana Department of Transportation's (INDOT's) strategic goals is to improve its pavement design procedures. This goal can be accomplished by fully implementing the 2002 mechanistic–empirical (M-E) pavement design guide (M-E PDG) once it is approved by AASHTO. The release of the M-E PDG software has provided a unique opportunity for INDOT engineers to evaluate, calibrate, and validate the new M-E design process. A continuously reinforced concrete pavement on I-65 was rubblized and overlaid with a 13–in.-thick hot-mix asphalt overlay in 1994. The availability of the structural design, material properties, and climatic and traffic conditions, in addition to the availability of performance data, provided a unique opportunity for comparing the predicted performance of this section using the M-E procedure with the in situ performance; calibration efforts were conducted subsequently. The 1993 design of this pavement section was compared with the 2002 M-E design, and performance was predicted with the same design inputs. In addition, design levels and inputs were varied to achieve the following: ( a) assess the functionality of the M-E PDG software and the feasibility of applying M-E design concepts for structural pavement design of Indiana roadways, ( b) determine the sensitivity of the design parameters and the input levels most critical to the M-E PDG predicted distresses and their impact on the implementation strategy that would be recommended to INDOT, and ( c) evaluate the rubblization technique that was implemented on the I-65 pavement section.

Optimal Offloading Configuration of Spread-Moored FPSOs

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Steven M. Wilkerson ◽  
Satish Nagarajaiah
Keyword(s):  
Environmental Conditions ◽  
Main Tool ◽  
Design Parameters ◽  
Optimization Approach ◽  
Analysis Model ◽  
Simple Analysis ◽  
Formal Approach ◽  
Fine Tune ◽  
Formal Optimization ◽  
Selection Of

As the oil offloading operations of floating production storage and offloading (FPSO) units become more routine, the desire grows to increase the availability for offloading and thus decrease production downtime. Experience with these operations is the main tool available to increase the efficiency of this aspect of deepwater production. However, it is clear that a formal optimization approach can help to fine tune design parameters so that not only is availability increased but the significance of each design parameter can be better understood. The key issue is to define the environmental conditions under which the vessels involved in offloading are able to maintain position. By this, we reduce the notion of availability to a set of operating criteria, which can or cannot be met for a particular set of environmental conditions. The actual operating criteria such as relative vessel heading depend on selection of design parameters, such as the direction and magnitude of external force applied by thrusters or tugs. In the earliest offloading operations, engineering judgment was used to determine the feasibility of offloading at a particular time. For example, if wind and current were not expected to exceed a 1year return period, offloading may be considered safe. This approach can be both conservative and unconservative, depending on the nuances of the particular environmental conditions. This study will propose a formal approach to choosing the design parameters that optimize the availability of a FPSO for offloading. A simple analysis model will be employed so that optimization can be performed quickly using a robust second order method. The proposed analysis model will be compared to model test data to demonstrate its agreement with the more complex system.

Stability Analysis for a Class of Linear Switched Positive Systems

2012 ◽  
Vol 562-564 ◽  
pp. 2084-2087
Author(s):  
Hui Ding ◽  
Xu Yang Lou
Keyword(s):  
Lyapunov Functions ◽  
Dwell Time ◽  
Positive Systems ◽  
Time Analysis ◽  
Arbitrary Switching ◽  
The Family ◽  
The Common ◽  
The Stability ◽  
Switched Positive Systems ◽  
Explicit Relation

This paper addresses stability properties of linear switched positive systems composed of continuous-time subsystems and discrete-time subsystems. Based on the common linear copositive Lyapunov functions, stability of the positive systems is discussed under arbitrary switching. Moreover, a sufficient condition on the minimum dwell time that guarantees the stability of linear switched positive systems. The dwell time analysis interprets the stability of linear switched positive systems through the distance between the eigenvector sets. Thus, an explicit relation in view of stability is obtained between the family of the involved subsystems and the set of admissible switching signals.

scholarly journals ON THE ISSUE OF DETERMINING THE CRITICAL CUTTING SPEED OF THE MECHANISM FOR FORMING AND TRIMMING THE FALSE EDGE OF THE DORNIER RAPIER LOOM

2021 ◽  
Vol 53 (3) ◽  
pp. 37-40
Author(s):  
Svitlana V. Bukina ◽  
Tatiana A. Sitnikova
Keyword(s):  
Rational Design ◽  
Mutual Influence ◽  
Cutting Speed ◽  
Design Parameters ◽  
Working Process ◽  
Forming Mechanism ◽  
Rational Design Parameters ◽  
Calculation Results ◽  
Knife Blade ◽  
The Impact

In this paper, an attempt is made to develop a method for determining the critical cutting speed of the threads of the false edge of the edge-forming mechanism of the weaving rapier machine. The proposed calculation method takes into account the impact nature of the cutting process at a critical speed, which allows taking into account the mutual influence of the parameters of the working process and more fully assess the mechanics of this process, in which the intensity of the cutting force and the value of the contact stress take the maximum value. The paper calculates the critical cutting speed for some of the main types of threads used and the parameters of the knife blade. The presented calculation results can be used to select rational design parameters of the knife blade, depending on the type of processed threads, when designing and researching new edge-forming mechanisms on looms.

Conceptual Design of Gear Differentials for Automotive Vehicles

1994 ◽  
Vol 116 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Hong-Sen Yan ◽  
Long-Chang Hsieh
Keyword(s):  
Conceptual Design ◽  
Degrees Of Freedom ◽  
Planetary Gear ◽  
Gear Train ◽  
Design Constraints ◽  
Two Degrees Of Freedom ◽  
Design Concepts ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
Gear Differential

An automotive gear differential is a joint-fractionated planetary gear train with two degrees-of-freedom. We summarize the characteristics of planetary gear trains and the design constraints of noncoupled automotive gear differentials to synthesize their corresponding kinematic graphs. Based on these graphs and the proposed respecializing process, we generate the atlas of design concepts for automotive gear differentials with any types of gear pairs. As a result, there are 4, 25, and 156 design concepts for five-, six-, and seven-bar automotive gear differentials, respectively.

scholarly journals Deflection Mechanism and Safety Analysis of Coal Mine Shaft in Deep Soil Strata

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Jihuan Han ◽  
Jiuqun Zou ◽  
Chenchen Hu ◽  
Weihao Yang
Keyword(s):  
Coal Mine ◽  
Rational Design ◽  
Coal Pillar ◽  
Design Parameters ◽  
Deep Soil ◽  
Mine Shaft ◽  
Dynamic Prediction ◽  
Probability Integral Method ◽  
Mining Conditions ◽  
Shaft Deflection

The main shaft and auxiliary shaft in the Guotun Coal Mine underwent large deflections, with deflection values of 359 mm and 322 mm, respectively. These two deflections represent the first occurrence of such large vertical shaft deviations in the soil strata in China. The deflection problem has seriously affected the hoisting safety and lining safety and has become a serious impediment to the sustainable production of mines. Therefore, the deflection mechanism must be determined. For this purpose, based on mining subsidence theory, the spatial probability integral method and a more accurate time function were used to establish a model, called 3D dynamic prediction model, for predicting the shaft movement. The formulas for calculating the lining stress caused by coal mining were based on established models. With measured shaft deflection data, the prediction parameters for deep soil strata were calculated on the basis of an inversion analysis. A comparative analysis of measured and calculated deflection values revealed that the reason for shaft deflection in Guotun Coal Mine is the insufficient size of the protection coal pillar (PCP); namely, the design parameters of the PCP in current codes are not applicable to the deep soil strata. As a result, under the asymmetric mining conditions, mining causes the shaft to deflect without damage and under the symmetric mining conditions, mining causes the lining to fracture. The results have an extremely important significance for the prevention and control of shaft deflection, for the rational design of PCP, and for the sustainability of mine production.

Kinematic Analysis and Prototyping of a Partially Decoupled 4-DOF 3T1R Parallel Manipulator

2006 ◽  
Vol 129 (6) ◽  
pp. 611-616 ◽  
Author(s):  
Pierre-Luc Richard ◽  
Clément M. Gosselin ◽  
Xianwen Kong
Keyword(s):  
Kinematic Analysis ◽  
Parallel Manipulator ◽  
Quadratic Equation ◽  
Design Stage ◽  
Forward Displacement ◽  
Singular Configurations ◽  
The Family ◽  
Moving Platform ◽  
Forward Displacement Analysis

A four-degree-of-freedom (DOF) 3T1R parallel manipulator is presented in this paper. This manipulator generates the family of so-called Schönflies motions, SCARA motions or 3T1R motions, in which the moving platform can translate in all directions and rotate around an axis of a fixed direction. The kinematic analysis of this architecture is presented, including the study of the constraint singular configurations, kinematic singular configurations, and the determination of the workspace. A prototype (the Quadrupteron) is also presented and demonstrated. The characteristics of the proposed prototype are (a) there is no constraint singularity, (b) its input-output equations are partially decoupled, (c) its kinematic singular configurations can be expressed using an equation in the angle of rotation of the moving platform and are thus easy to avoid at the design stage, and (d) its forward displacement analysis requires the solution of a univariate quadratic equation and can therefore be solved efficiently.

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