scholarly journals A Mathematical Model for Calculating Deviations of the Shape, Size and Geometric Relationship of Flat Surfaces

2016 ◽  
Vol 16 (02) ◽  
Author(s):  
I Kravchenko
Keyword(s):  
Mathematical Model ◽  
Flat Surfaces ◽  
Geometric Relationship ◽  
Relationship Of

Mathematical Model of Flat Surface Machining Inaccuracies due to Elastic Strains of Technological System

2018 ◽  
pp. 1-14 ◽  
Author(s):  
I. I. Kravchenko
Keyword(s):  
Mathematical Model ◽  
Vector Field ◽  
Model Development ◽  
Technological System ◽  
Mutual Arrangement ◽  
Real Surface ◽  
Main Bearing ◽  
Flat Surfaces ◽  
Internal Surfaces ◽  
Elastic Strains

The paper considers the mathematical model development technique to build a vector field of the shape deviations when machining flat surfaces of shell parts on multi-operational machines under conditions of anisotropic rigidity in technological system (TS). The technological system has an anisotropic rigidity, as its elastic strains do not obey the accepted concepts, i.e. the rigidity towards the coordinate axes of the machine is the same, and they occur only towards the external force. The record shows that the diagrams of elastic strains of machine units are substantially different from the circumference. The issues to ensure the specified accuracy require that there should be mathematical models describing kinematic models and physical processes of mechanical machining under conditions of the specific TS. There are such models for external and internal surfaces of rotation [2,3], which are successfully implemented in practice. Flat surfaces (FS) of shell parts (SP) are both assembly and processing datum surfaces. Therefore, on them special stipulations are made regarding deviations of shape and mutual arrangement. The axes of the main bearing holes are coordinated with respect to them. The joints that ensure leak tightness and distributed load on the product part are closed on these surfaces. The paper deals with the analytical construction of the vector field F, which describes with appropriate approximation the real surface obtained as a result of modeling the process of machining flat surfaces (MFS) through face milling under conditions of anisotropic properties.

scholarly journals Development of a Novel Double-Ring Deployable Mesh Antenna

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Yan Xu ◽  
Fuling Guan ◽  
Xian Xu ◽  
Hongjian Wang ◽  
Yao Zheng
Keyword(s):  
Low Frequency ◽  
Design Concept ◽  
Design Parameters ◽  
Accuracy Measurement ◽  
Double Ring ◽  
Reflective Surface ◽  
Final Design ◽  
Geometric Relationship ◽  
Relationship Of ◽  
Adjustment Test

This paper addresses a type of deployable mesh antenna consisting of the double-ring deployable truss edge frame and the cable net reflector. The structural design concept of the deployable antennas is presented. The deployable truss is designed and the geometric relationship of each strut length is formulated. Two types of radial truss elements are described and compared. The joint pattern and the active cables of the final design concept are determined. The pattern of the cable net is the three-orientation grid. Two connection schemes between the reflector and the deployable edge frame are investigated. The design parameters and the shape adjustment mechanism of this cable net are determined. The measurement test technologies of the antennas on the ground including test facilities, deployment test, and measurement and adjustment test are proposed. The antenna patterns are analyzed based on the real surfaces of the reflector obtained by the reflective surface accuracy measurement. The tests and analytic results indicated that the accuracy of the reflective surface is high and is suitable for low-frequency communication.

Design of the Conjugate Cam Induction Hardening Mechanism and Establishment of the Motion Controlling Mathematical Model

2012 ◽  
Vol 155-156 ◽  
pp. 726-730
Author(s):  
Zhong Hua Li ◽  
Qian Tang ◽  
Di Yan ◽  
Jie Wu
Keyword(s):  
Mathematical Model ◽  
Induction Hardening ◽  
Uniform Motion ◽  
Hardening Mechanism ◽  
Kinematic Relationship ◽  
Nc Machine ◽  
The Common ◽  
Relationship Of ◽  
The Mathematical Model ◽  
Basic Motion

The common methods of cam induction hardening are discussed at present. By analyzing the basic motion law of conjugate cam, a new induction hardening mechanism is designed. The motion controlling mathematical model is built on the basis of the kinematic relationship of the transmission of the induction hardening mechanism. Through the mathematical model calculation, we can get angular velocity of the workbench, then realize that single axis on NC machine controls the inductor to make isometric uniform motion relative to the cam surface, so that the cam hardening depth distribution is uniform.

scholarly journals Relation between swine weight and morphometric measurements

2020 ◽  
Vol 9 (9) ◽  
pp. e891998013
Author(s):  
Mônica Calixto Ribeiro de Holanda ◽  
Marco Aurélio Carneiro de Holanda ◽  
Leandro Ricardo Rodrigues de Lucena
Keyword(s):  
Mathematical Model ◽  
Body Weight ◽  
Regression Models ◽  
Hip Circumference ◽  
Morphometric Measurements ◽  
Large White ◽  
Male And Female ◽  
Lactation Phase ◽  
Relationship Of ◽  
The Relationship

Objective was to define a mathematical model that better explain the relationship of the animals weight depending not only on the animals age but also on the animals morphometric measurements. 40 piglets, half Duroc-Large White blood, were used, 20 males and 20 females, from 3 to 35 days of age (lactation phase) initially weighing 1.518 ± 0.121 kg and from 36 to 66 days of age (calving phase) with a body weight of 7.010 ± 0.704 kg. The animals were weighed weekly on a digital balance. The relationship of animal weight, age and morphometric measurements of male and female piglets were performed using regression models: existing, linear and power. The models were evaluated according to nine criterialinear model was the most adequate to explain the weight of male pigs, while for female pigs was the power. The age of the pig, the shank and palette length, as well as the circumference of the shank jointly explain the weight of the male piglets. The weight of females is explained jointly by age, body length, thorax and hip circumference.

Establishment of Relatively Unified Mathematical Model for Spiral Surface Based on Movement Characteristics of Particle

2010 ◽  
Vol 455 ◽  
pp. 1-5
Author(s):  
L.Z. Song ◽  
S.L. Guo ◽  
Chun Jiang Xiang ◽  
Qi Hong
Keyword(s):  
Mathematical Model ◽  
Surface Shape ◽  
Movement Characteristics ◽  
Spiral Surface ◽  
Relationship Of ◽  
First Time ◽  
The Relationship

From the viewpoint of the forming principle of spiral curve and classification from the kinematics, established relatively unified mathematical model of spiral curve based on the movement characteristics of particle and the forming principle of space surface shape, and in turn relying on relatively unified mathematical model of spiral curve, combined the similarity of forming movement between spiral curve and spiral surface, derived the relatively unified mathematical model of spiral surface with the concept of sequence of operator presented for the first time. The relatively unified mathematical model has been validated that it not only expressed the relationship of movement synthesis for commonly spiral surface’s forming movement, but also depicted new spiral surface to be required or named through changing parameters.

Model based design of antagonistic shape memory alloy spring devices

2018 ◽  
Vol 29 (12) ◽  
pp. 2619-2640 ◽  
Author(s):  
Efthymios Kolyvas ◽  
Anthony Tzes
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Model Based ◽  
Operational Profile ◽  
Time Work ◽  
Two Factors ◽  
Internal Forces ◽  
Actuation Scheme ◽  
Geometric Relationship ◽  
Relationship Of

Shape memory alloy actuated devices employing a network of antagonistic components can reach an equilibrium of the internal forces by multiple sets of individual force magnitudes. In networks of star topologies particularly, the actuators are placed radially with one end connected at a common node. The ability to produce multiple sets of force equilibria suggests then that similar motions of the common node correspond to different thermomechanical paths. Two factors linked to this behavior are examined in this work, namely the initial design of the antagonistic system and the operational profile used during actuation. A shape memory alloy model is initially constructed based on an elementary hysteresis operator to produce a direct representation of the shape memory alloy behavior in the force–deformation plane. This description enables the identification of the operating point for the actuator by the geometric relationship of these models. In the second part, the placement of the antagonists is guided by the model based on specifications on the range of the workspace and the internal forces. The antagonistic operation is finally compared, in terms of time, work produced, and energy consumption, for a bang-bang (minimum time controller for the actuator) and a bang-off-bang (minimum internal forces for the system) actuation scheme.

Automatic Parameter Identification Applied to a Railroad Car Dynamic Draft Gear Model

1974 ◽  
Vol 96 (4) ◽  
pp. 460-465 ◽  
Author(s):  
E. D. Ward ◽  
R. G. Leonard
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Parameter Identification ◽  
Functional Relationship ◽  
Nonlinear Functional ◽  
Draft Gear ◽  
Identification Technique ◽  
Train Dynamics ◽  
Relationship Of ◽  
The Mathematical Model

One of the most important components in simulating track-train dynamics is the mathematical model of the connection between two cars, the draft gear-coupler combination. In this paper an automatic parameter identification technique is presented which can be used to generate a nonlinear functional relationship of dynamic draft gear characteristics using experimental data.

Study on High Frequency Hydraulic Exciter Based on Rotary Valve Control

2012 ◽  
Vol 490-495 ◽  
pp. 1441-1445 ◽  
Author(s):  
Jian Zhuo Zhang ◽  
Li Zhe Guan ◽  
Kang Kang Li
Keyword(s):  
Mathematical Model ◽  
High Frequency ◽  
Rotary Valve ◽  
Exciting Frequency ◽  
Working Principle ◽  
Relationship Of ◽  
The Mathematical Model ◽  
The Relationship ◽  
Valve Control

A kind of hydraulic exciter based on rotary valve control was studied in this paper, the composition of the exciter and its working principle were introduced, and the mathematical model of the system was established. The characters of the system were simulated using MATLAB. From the results of the simulation, we get the relationship of the amplitude of Vibration oil cylinder between the system’s pressure and the exciting frequency. The results can provide theoretical bases to design the hydraulic exciter.

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