Inter-particle force vectors and inter-particle stress vectors

2019 ◽  
pp. 59-95
Author(s):  
Ryosuke Kitamura ◽  
Kazunari Sako
Keyword(s):  
Particle Force ◽  
Force Vectors

scholarly journals Variable Thumb Moment Arm Modeling and Thumb-Tip Force Production of a Human-Like Robotic Hand

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Taylor D. Niehues ◽  
Ashish D. Deshpande
Keyword(s):  
Physical Simulation ◽  
Three Dimensional ◽  
Force Production ◽  
Human Hand ◽  
Robotic Hand ◽  
Motion Data ◽  
Moment Arms ◽  
Musculoskeletal Structure ◽  
Thumb Motion ◽  
Force Vectors

The anatomically correct testbed (ACT) hand mechanically simulates the musculoskeletal structure of the fingers and thumb of the human hand. In this work, we analyze the muscle moment arms (MAs) and thumb-tip force vectors in the ACT thumb in order to compare the ACT thumb's mechanical structure to the human thumb. Motion data are used to determine joint angle-dependent MA models, and thumb-tip three-dimensional (3D) force vectors are experimentally analyzed when forces are applied to individual muscles. Results are presented for both a nominal ACT thumb model designed to match human MAs and an adjusted model that more closely replicates human-like thumb-tip forces. The results confirm that the ACT thumb is capable of faithfully representing human musculoskeletal structure and muscle functionality. Using the ACT hand as a physical simulation platform allows us to gain a better understanding of the underlying biomechanical and neuromuscular properties of the human hand to ultimately inform the design and control of robotic and prosthetic hands.

Shear Flow Analysis of Nanosize Particle Flow Behavior Using Kinetic Theory

2005 ◽  
Vol 277-279 ◽  
pp. 939-944
Author(s):  
Hae Ryung Kim ◽  
Jaihyun Seu ◽  
Hamid Arastoopour
Keyword(s):  
Shear Flow ◽  
Kinetic Theory ◽  
Flow Behavior ◽  
Flow Analysis ◽  
Particle Diameter ◽  
Particle Flow ◽  
Particle Collision ◽  
Simple Shear Flow ◽  
Particle Force ◽  
Nanosize Particle

Nanosize particle flow is significantly affected by inter-particle force. Due to the inter-particle force, the most significant characteristic of nanosize particle flow may become the formation of agglomerates or clusters which considerably affects the flow patterns. The formation of agglomerates or clusters results in a reduction in the number and an increase in the size of particles, both of which directly affect the frequency of inter-particle collisions and, in turn, the particle phase properties such as viscosity and pressure, as well as gas/particle drag force in gas/particle flow systems. In this present work, we focus our attention on the verification of nanosize particle flow behavior due to the formation of agglomerates or clusters under different fluctuation of flow and inelasticity of particle collision. By extending the application of the cohesive model using kinetic theory to nanosize particle flow system, we performed the homogeneous simple shear flow analysis using various fluctuation energy and restitution coefficient. The predicted flow properties, such as particle diameter growth, agreed well with the expected trends.

scholarly journals Sagittal plane fore hoof unevenness is associated with fore and hindlimb asymmetrical force vectors in the sagittal and frontal planes

PLoS ONE ◽  
2018 ◽  
Vol 13 (8) ◽  
pp. e0203134 ◽  
Author(s):  
Sarah Jane Hobbs ◽  
Sandra Nauwelaerts ◽  
Jonathan Sinclair ◽  
Hilary M. Clayton ◽  
Willem Back
Keyword(s):  
Sagittal Plane ◽  
Force Vectors

Force Evaluation of Tendon Routing for Underactuated Grasping

2021 ◽  
pp. 1-9
Author(s):  
Angus B. Clark ◽  
Lois Liow ◽  
Nicolas Rojas
Keyword(s):  
Optimum Condition ◽  
Theoretical Models ◽  
External Factors ◽  
Experimental Comparison ◽  
Adaptive Behaviour ◽  
Joint Torques ◽  
Contact Points ◽  
Single Finger ◽  
Modelling Analysis ◽  
Force Vectors

Abstract While the modelling analysis of the kinetostatic behaviour of underactuated tendon-driven robotic fingers has been largely addressed in the literature, tendon routing is often not considered by these theoretical models. Tendon routing path plays a fundamental role in defining joint torques, and subsequently the force vectors produced by the phalanxes. However, dynamic tendon behaviour is difficult to predict and is influenced by many external factors including tendon friction, the shape of the grasped object, the initial pose of the fingers, and finger contact points. In this paper, we present an experimental comparison of the force performance of nine fingers, with different tendon routing configurations. We use the concept of force-isotropy, in which forces are equal and distributed on each phalanx as the optimum condition for an adaptive grasp. Our results show only some of the finger designs surveyed exhibited a partial adaptive behaviour, showing distributed force for the proximal and distal phalanxes throughout grasping cycles, while other routings resulted in only a single finger remaining in contact with the object.

A New Lower Extremity Modeling of Human Body With Variable Feet Links

2000 ◽  
Author(s):  
Nader Arafati ◽  
Jean Yves Lazennec ◽  
Roger Ohayon
Keyword(s):  
Ground Reaction Force ◽  
Sagittal Plane ◽  
Reaction Force ◽  
Human Movement ◽  
Knee Joints ◽  
Foot Pressure ◽  
Ankle Joints ◽  
Reaction Forces ◽  
Human Movement Modeling ◽  
Force Vectors

Abstract Human movement modeling has been the object of much research for the past 30 years. In these models the position of foot link was fixed on the ground. We propose to model the feet links as variable, since the position of foot pressure center changes from heel to toes. The ground reaction forces could also be analyzed in real time. We examined this model for some static postures. In standing anatomical position, the maximum articular forces are localized in hip and knee joints. In sagittal plane, the ground reaction force vectors are positioned nearly under ankle joints. The pathological postures like body with pes cavus or with global spine kyphosis increase the articular and muscular forces. In these cases, the position of ground reaction force vectors is moved toward the toes.

Prediction of Water Circulation Characteristics in a 4-Pass Firetube Boiler With the Non-Symmetric Arrangement of Tube Passes 3 and 4

2001 ◽  
Author(s):  
Hyunjae Park ◽  
Anthony Bowman ◽  
Tod Stansfield ◽  
Brian Huibregtse ◽  
Steve Wilkinson ◽  
...  
Keyword(s):  
Nucleate Boiling ◽  
Relative Difference ◽  
Furnace Wall ◽  
Water Circulation ◽  
Feed Water ◽  
Attraction Force ◽  
Boiler Furnace ◽  
Nucleate Boiling Heat Transfer ◽  
Circulation Characteristics ◽  
Force Vectors

Abstract Water circulation characteristics, for a newly designed 4-pass 300 BHP (Boiler Horse Power) firetube boiler with a non-symmetric arrangement of tube passes 3 and 4, are investigated in this paper by means of measured furnace wall temperatures for different boiler firing conditions. Vapor production rate and intensity, at each of the 28 temperature measurement nodes, is approximated using the nodal temperature in conjunction with a nucleate boiling heat transfer mode on the water side of the furnace. Defining an attraction force that is proportional to the relative difference of the evaporation intensity between two nodes and inversely proportional to the distance between, the two-dimensional components of the attraction force can be calculated. Integrating all attraction force vectors between a node and the surrounding nodes produces a representative attraction force vector at the node. Similar calculation of the attraction force vectors at all of the temperature nodes on the furnace wall will characterize the water circulation near the boiler furnace. Investigations of the analysis results reveal various complicated non-symmetric water circulation patterns for different boiler firing conditions. Consequently, the analysis methods employed in this paper can be used to predict and improve the water circulation in a firetube boiler, particularly with regard to the placement of the boiler feed-water inlet location.

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