Towards a Recursive Hexapod for the Multidimensional Mechanical Testing of Composites

2010 ◽  
Author(s):  
John G. Michopoulos ◽  
John C. Hermanson ◽  
Athanasios Iliopoulos
Keyword(s):  
Composite Material ◽  
Boundary Conditions ◽  
Mechanical Testing ◽  
Material Testing ◽  
Inverse Methods ◽  
Current Status ◽  
Historical Evolution ◽  
Mechatronic System ◽  
Custom Design ◽  
Reaction Forces

Automated inverse methods for material constitutive characterization under multidimensional loading conditions has motivated the custom design, manufacturing and utilization of mechatronic loading machines. This present paper reports on the architecture of a mechatronic system capable of enforcing 6-DoF kinematic boundary conditions on deformable material specimens under testing, while at the same time measuring both the imposed kinematics and the corresponding reaction forces in a fully automated manner. This system has a recursive nature as it consists of a hexapod configuration that repeats itself six times. In addition to the architecture, we also present the historical evolution, and current status of its manufacturing implementation and the initial fielding of our system for composite material testing and characterization.

Design of NRL66.4: An Electro-Hydraulic 6-DoF Parallel Robotic Multiaxial Material Testing System

2019 ◽  
Author(s):  
John G. Michopoulos ◽  
Athanasios P. Iliopoulos ◽  
John C. Steuben ◽  
Benjamin D. Graber
Keyword(s):  
Degrees Of Freedom ◽  
Material Testing ◽  
Multiaxial Fatigue ◽  
Current Status ◽  
Testing System ◽  
Damage Propagation ◽  
Propagation Modeling ◽  
Multiaxial Testing ◽  
Reaction Forces ◽  
6 Degrees Of Freedom

Abstract Contemporary material testing applications such as high throughput material testing under realistic conditions, emulation of in-service loading conditions for the qualification of additively manufactured parts, material failure and damage propagation modeling validation and material constitutive characterization, are all underscoring the demand for an automated multiaxial testing capability. In order to address these needs, the present work introduces the initial progress of the design and prototyping of a 6 degrees of freedom (6-DoF) robotic system to be used as such a testing infrastructure. This system is designed to be capable of enforcing 6-DoF kinematic or force controlled boundary conditions on deformable material specimens, while at the same time measuring both the imposed kinematics and the corresponding reaction forces in a fully automated manner. Furthermore, as an extension to our previously prototyped systems, the system proposed here is designed to apply both quasi-static loading but also cyclic loading for enabling multiaxial fatigue studies. In addition to the architecture, the design and current status of its implementation for the most critical sub-systems is presented.

scholarly journals MECHANICAL TESTING OF NEW NATURAL FIBRE REINFORCED COMPOSITE MATERIAL

2021 ◽  
Vol Special (June) ◽  
pp. 29-39
Author(s):  
Ravi Prakash Sharma ◽  
Jitendra Dixit ◽  
Abhijeet Jaiswal ◽  
Nalin Sharma
Keyword(s):  
Composite Material ◽  
Mechanical Testing ◽  
Natural Fibre ◽  
Reinforced Composite ◽  
Reinforced Composite Material

Telemedicine as a Modality of Health Care Delivery and its Implications

2012 ◽  
pp. 620-633 ◽  
Author(s):  
Rashid L Bashshur ◽  
Gary W Shannon
Keyword(s):  
Health Care ◽  
Health Care Delivery ◽  
Common Good ◽  
Care Delivery ◽  
Current Status ◽  
Historical Evolution ◽  
Risk Avoidance ◽  
Isolated Populations ◽  
The Common ◽  
Limited Diffusion

This chapter provides both formal and operational definitions of telemedicine as well as the related concepts of telehealth, e-health, and m-health, and reviews the origin and historical evolution of the nomenclature and content of telemedicine over the last century. The rationale for telemedicine is discussed in terms of potential effects on improving access to care, especially for underserved, remote and isolated populations, redressing inequities in quality and cost containment in terms of greater efficiency and risk avoidance, not only singly but also symbiotically. The current status of telemedicine and the reasons for its limited diffusion to date are discussed. Finally, the empirical evidence is briefly reviewed, selecting one application as an example. The chapter concludes with an optimistic expectation of continued proliferation of the field to serve the common good.

scholarly journals Role of Piezoelectric Elements in Finding the Mechanical Properties of Solid Industrial Materials

2018 ◽  
Vol 8 (10) ◽  
pp. 1737 ◽  
Author(s):  
Arshed Mohammed ◽  
Sallehuddin Haris ◽  
Mohd Nuawi
Keyword(s):  
Mechanical Properties ◽  
State Of The Art ◽  
New Technology ◽  
Material Testing ◽  
Current Status ◽  
Piezoelectric Elements ◽  
Need To Evaluate ◽  
Recent Developments ◽  
The Many

Recent developments in ultrasonic material testing have increased the need to evaluate the current status of the different applications of piezoelectric elements (PEs). This research have reviewed state-of-the-art emerging new technology and the role of PEs in tests for a number of mechanical properties, such as creep, fracture toughness, hardness, and impact toughness, among others. In this field, importance is given to the following variables, namely, (a) values of the natural frequency to PEs, (b) type and dimensions of specimens, and (c) purpose of the tests. All these variables are listed in three tables to illustrate the nature of their differences in these kinds of tests. Furthermore, recent achievements in this field are emphasized in addition to the many important studies that highlight the role of PEs.

Modelling and vibration of composite thin-walled rotating blades featuring extension-twist elastic coupling

2005 ◽  
Vol 109 (1095) ◽  
pp. 233-246 ◽  
Author(s):  
S-Y. Oh ◽  
L. Librescu ◽  
O. Song
Keyword(s):  
Composite Material ◽  
Boundary Conditions ◽  
Cross Sections ◽  
Equations Of Motion ◽  
Physical Characteristics ◽  
Elastic Coupling ◽  
Hamilton’S Principle ◽  
Rotating Blades ◽  
Advanced Composite ◽  
Thin Walled

Abstract The modelling and vibration of composite thin-walled pre-twisted rotating blades of non-uniform cross-sections along their span, and featuring the extension-twist elastic coupling are addressed. To this end, Hamilton’s principle is used to derive the equations of motion and the associated boundary conditions. In addition to the pretwist and warping restraint, the exotic properties of advanced composite material are used, and the efficiency of implementing the tailoring technique toward the enhancement, without weight penalties, of the vibratory behaviour of rotating blades is illustrated. Comparisons between the predictions by both Wagner’s and Washizu’s approaches are presented, and pertinent conclusions regarding the implications of the various geometrical and physical characteristics of the blade are outlined.

scholarly journals The (Unequal) Relationship between Hong Kong’s Waters and China’s Baselines

2019 ◽  
Vol 4 (1) ◽  
pp. 1-27
Author(s):  
Nina H.B. Jørgensen
Keyword(s):  
Hong Kong ◽  
Future Development ◽  
Reference Point ◽  
Status Quo ◽  
Current Status ◽  
Historical Evolution ◽  
Historical Inquiry ◽  
Legal Relationship ◽  
Baseline System

This article aims to clarify the legal relationship between Hong Kong’s maritime areas and China’s baseline system by conducting an historical inquiry into how the current status quo was reached and considering the implications for Hong Kong’s future development. China’s well-known position is that the treaties granting authority to the British in Hong Kong, including the ninety-nine year lease of the New Territories, were ‘unequal’ and therefore invalid so that sovereignty over the land and waters of Hong Kong never left Chinese hands and this position would be recognized and remedied at the appropriate time. As the Hong Kong experience illustrates, when territory is surrendered or leased, rights and claims are altered and sometimes extended. The historical evolution of those rights and claims therefore impacts on current territorial relationships. The example of Hong Kong may additionally serve as a reference point for modern day lease arrangements concerning coastal territory made outside the colonial context.

Development of Composite Material Testing Facility for Cryogenic Fuel Tank Applications

2015 ◽  
Vol 4 (5) ◽  
pp. 314-317
Author(s):  
Sandeep Singh ◽  
Karthik Sunil ◽  
Prudhvinath Reddy ◽  
Idris Syed Mahaboob ◽  
Raja Sekhar Dondapati
Keyword(s):  
Composite Material ◽  
Material Testing ◽  
Fuel Tank ◽  
Testing Facility
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