Parameter analysis of water flow during EPBS tunnelling and an evaluation method of spewing failure based on a simplified model

2015 ◽  
Vol 58 ◽  
pp. 96-112 ◽  
Author(s):  
Gang Zheng ◽  
Xuan Dai ◽  
Yu Diao
Keyword(s):  
Water Flow ◽  
Evaluation Method ◽  
Parameter Analysis ◽  
Simplified Model

scholarly journals Development of Simplified Model Test Methods for Creep-Fatigue Evaluation

2019 ◽  
Author(s):  
Y. Wang ◽  
B. Jetter ◽  
M. C. Messner ◽  
T.-L. Sham
Keyword(s):  
Model Test ◽  
Evaluation Method ◽  
Test Methods ◽  
Simplified Model ◽  
Test Results ◽  
Interaction Diagram ◽  
Creep Fatigue ◽  
Fatigue Evaluation ◽  
Creep Regime ◽  
Further Development

Abstract The Simplified Model Test (SMT) approach is an alternative creep-fatigue evaluation method that no longer requires the use of the damage interaction diagram, or D-diagram. The reason is that the combined effects of creep and fatigue are accounted for in the test data by means of a SMT specimen that is designed to replicate or bound the stress and strain redistribution that occurs in actual components when loaded in the creep regime. However, creep-fatigue experiments on SMT key feature articles are specialized and difficult to perform by the general research community. In this paper, two innovative SMT based creep-fatigue experimental methods are developed and implemented. These newly-developed SMT test methods have resolved all the critical challenges in the SMT key feature article testing and enable the potential of further development of the SMT based creep-fatigue evaluation method into a standard testing method. Scoping test results on Alloy 617 and SS 316H using the newly developed SMT methods are summarized and discussed. The concepts of the SMT methodology for creep-fatigue evaluation are explained.

Parameter Analysis of the Differential Model of Hysteresis

2004 ◽  
Vol 71 (3) ◽  
pp. 342-349 ◽  
Author(s):  
F. Ma ◽  
H. Zhang ◽  
A. Bockstedte ◽  
G. C. Foliente ◽  
P. Paevere
Keyword(s):  
Monte Carlo ◽  
Relative Sensitivity ◽  
Nonlinear Damping ◽  
Parameter Analysis ◽  
Sensitivity Analyses ◽  
Simplified Model ◽  
Hysteretic Model ◽  
Differential Model ◽  
Global Sensitivity

The extended Bouc-Wen differential model is one of the most widely accepted phenomenological models of hysteresis in mechanics. It is routinely used in the characterization of nonlinear damping and in system identification. In this paper, the differential model of hysteresis is carefully reexamined and two significant issues are uncovered. First, it is shown that the unspecified parameters of the model are functionally redundant. One of the parameters can be eliminated through suitable transformations in the parameter space. Second, local and global sensitivity analyses are conducted to assess the relative sensitivity of each model parameter. Through extensive Monte Carlo simulations, it is found that some parameters of the hysteretic model are rather insensitive. If the values of these insensitive parameters are fixed, a greatly simplified model is obtained.

A new modelling approach to simulate preferential flow and transport in water repellent porous media: Parameter sensitivity, and effects on crop growth and solute leaching

Soil Research ◽  
2005 ◽  
Vol 43 (3) ◽  
pp. 371 ◽  
Author(s):  
G. Kramers ◽  
J. C. van Dam ◽  
C. J. Ritsema ◽  
F. Stagnitti ◽  
K. Oostindie ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Flow ◽  
Crop Production ◽  
Preferential Flow ◽  
Crop Growth ◽  
Parameter Sensitivity ◽  
Uniform Flow ◽  
Parameter Analysis ◽  
Water Repellent ◽  
Soil Water Flow

A modified version of the popular agrohydrological model SWAP has been used to evaluate modelling of soil water flow and crop growth at field situations in which water repellency causes preferential flow. The parameter sensitivity in such situations has been studied. Three options to model soil water flow within SWAP are described and compared: uniform flow, the classical mobile-immobile concept, and a recent concept accounting for the dynamics of finger development resulting from unstable infiltration. Data collected from a severely water-repellent affected soil located in Australia were used to compare and evaluate the usefulness of the modelling options for the agricultural management of such soils. The study shows that an assumption of uniform flow in a water-repellent soil profile leads to an underestimation of groundwater recharge and an overestimation of plant transpiration and crop production. The new concept of modelling taking finger dynamics into account provides greater flexibility and can more accurately model the observed effects of preferential flow compared with the classical mobile–immobile concept. The parameter analysis indicates that the most important factor defining the presence and extremity of preferential flow is the critical soil water content. Comparison of the modelling results with the Australian field data showed that without the use of a preferential flow module, the effects of the clay amendments to the soil were insufficiently reproduced in the dry matter production results. This means that the physical characteristics of the soil alone are not sufficient to explain the measured increase in production on clay amended soils. However, modelling with the module accounting for finger dynamics indicated that the preferential flow in water repellent soils that had not been treated with clay caused water stress for the crops, which would explain the decrease in production.

scholarly journals Athlete Rehabilitation Evaluation System Based on Internet of Health Things and Human Gait Analysis Algorithm

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Chen Lianzhen ◽  
Zhu Hua
Keyword(s):  
Gait Analysis ◽  
Evaluation System ◽  
Evaluation Method ◽  
Simulation Analysis ◽  
Parameter Analysis ◽  
Human Gait ◽  
Good Effect ◽  
The Internet ◽  
Analysis Algorithm ◽  
Human Gait Analysis

In order to improve the effect of athlete’s injury recognition and rehabilitation evaluation, this paper studies the traditional rehabilitation evaluation method and proposes a new athlete rehabilitation evaluation system combining the Internet of Health Things technology and human gait analysis algorithm. Moreover, this paper combines sports characteristics to improve the algorithm of human gait analysis. In addition, through the study of the athlete’s human body modeling and movement process, a human gait analysis algorithm that can be applied to multiple sports is proposed, and the gait parameter analysis and algorithm reliability research are carried out through simulation analysis. After confirming that the algorithm is effective, this paper combines the Internet of Health Things technology to construct a system model, obtains the system function module architecture with the support of the Internet of Health Things technology, and conducts experiments to verify the system performance. From the experimental research, it can be seen that the model constructed in this paper meets the theoretical and practical needs, and the system in this paper can be applied to practice in the future. The human gait recognition algorithm constructed in this article has a good effect and can play an important role in sports rehabilitation of athletes. At the same time, the system constructed in this article has certain advantages over traditional sports rehabilitation systems with the support of algorithms.

A Simplified Model for Oil/Water Flow in Vertical and Deviated Wellbores

1999 ◽  
Vol 14 (01) ◽  
pp. 56-62 ◽  
Author(s):  
A.R. Hasan ◽  
C.S. Kabir
Keyword(s):  
Water Flow ◽  
Simplified Model ◽  
Oil Water
Sign in / Sign up

Export Citation Format

Share Document