Dynamic Behavior of Soil in Compression by Propagation of Stress Waves with a Tillage Tool

1972 ◽  
Vol 15 (6) ◽  
pp. 1031-1034 ◽  
Author(s):  
Ram Krishna and C. P. Gupta
Keyword(s):  
Dynamic Behavior ◽  
Stress Waves

scholarly journals Dynamic Behavior of Fault Slip Induced by Stress Waves

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Guang-an Zhu ◽  
Lin-ming Dou ◽  
Yang Liu ◽  
Zhen-guo Su ◽  
Hui Li ◽  
...  
Keyword(s):  
Rock Burst ◽  
Dynamic Behavior ◽  
Stress Relief ◽  
Fault Slip ◽  
Stress Waves ◽  
Fault Rock ◽  
Dynamic Disturbance ◽  
Static And Dynamic Analysis ◽  
Disturbance Intensity ◽  
Mining Depth

Fault slip burst is a serious dynamic hazard in coal mining. A static and dynamic analysis for fault slip was performed to assess the risk of rock burst. A numerical model FLAC3D was established to understand the stress state and mechanical responses of fault rock system. The results obtained from the analysis show that the dynamic behavior of fault slip induced by stress waves is significantly affected by mining depth, as well as dynamic disturbance intensity and the distance between the stope and the fault. The isolation effect of the fault is also discussed based on the numerical results with the fault angle appearing to have the strongest influence on peak vertical stress and velocity induced by dynamic disturbance. By taking these risks into account, a stress-relief technology using break-tip blast was used for fault slip burst control. This technique is able to reduce the stress concentration and increase the attenuation of dynamic load by fracturing the structure of coal and rock. The adoption of this stress-relief method leads to an effective reduction of fault slip induced rock burst (FSIRB) occurrence.

Dynamic Damage in Certain Monolithic Ceramic Materials

1991 ◽  
Vol 58 (3) ◽  
pp. 639-643 ◽  
Author(s):  
A. E. Giannakopoulos
Keyword(s):  
Dynamic Response ◽  
Dynamic Behavior ◽  
Constitutive Relation ◽  
Ceramic Materials ◽  
Stress Waves ◽  
Material Behavior ◽  
Plastic Behavior ◽  
Longitudinal Stress ◽  
Monolithic Ceramics ◽  
Dynamic Damage

In the present work, the propagation of elasto-damage longitudinal stress waves in thin rods is investigated. The material behavior is characteristic to that of certain monolithic ceramics. The damage constitutive relation that characterizes this type of materials gives rise to certain dynamic behavior which is somewhat different from dynamic plastic behavior. Plastic and damage dynamic response are compared through an example.

Dynamic Behavior of Stress Waves in Blasting Process

2004 ◽  
Vol 465-466 ◽  
pp. 55-60
Author(s):  
S. Matsumoto ◽  
Y. Nakamura ◽  
Shigeru Itoh
Keyword(s):  
Dynamic Behavior ◽  
Stress Waves

Interaction of Stress Waves From a Pair of Charge Holes in PMMA

2006 ◽  
Author(s):  
S. Matsumoto ◽  
Y. Nakamura ◽  
S. Itoh
Keyword(s):  
Dynamic Behavior ◽  
Control Method ◽  
Stress Waves ◽  
Sph Method ◽  
Visualization System ◽  
Fracture Planes ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Fracture Control ◽  
Smooth Blasting

Fracture control in blasting is very important in underground excavation and demolition of concrete structures. It is valuable to obtain an understanding of the dynamic behavior of stress waves in the blasting process for the development of fracture control method. Experimental visualizations and numerical simulations were performed to observe the propagation and interaction of stress waves between two charge holes in blasting. These are related with control of fracture planes along the line connecting the charge holes in smooth blasting. In model experiments using PMMA plates, the stress waves were generated by initiation of electric detonators at the charge holes and were observed by means of the visualization system. The dynamic behavior of stress waves in the blasting process was also visualized by numerical simulation using the smoothed particle hydrodynamics (SPH) method. The dynamic behavior of stress waves is discussed by means of the experimental results and the simulation results.

Ball bearing turbocharger vibration management: application on high speed balancer

2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Ball Bearing ◽  
Squeeze Film ◽  
Design And Technology ◽  
Squeeze Film Damper ◽  
Damping Coefficients ◽  
Bearing Loads ◽  
Stiffness And Damping

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.

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