Experimental Investigation into Spall of Carbon Phenolic Composites

2014 ◽  
Vol 887-888 ◽  
pp. 62-69
Author(s):  
Zhi Gang Zhu ◽  
Yong Chi Li
Keyword(s):  
Free Surface ◽  
Spall Strength ◽  
State Equation ◽  
Physical Characteristics ◽  
Hugoniot Curve ◽  
Gas Gun ◽  
Tensile Wave ◽  
History Of ◽  
Surface Particle ◽  
Velocity History

The velocity history of free-surface particle for carbon phenolic composites (density is 1.4g/cm3) is obtained based on the loading technology of the light gas gun, the relationship between the striking velocity of flyer and the spall thickness as well as time is investigated. Besides, spall strength and thickness are obtained by analyzing the samples data and curves. The high pressure physical characteristics, such as type Hugoniot curve and Murnagham state equation for this material, are acquired by analyzing the velocity history of free-surface and spall characteristics. This study provides a methodology to quantify spall and physical characteristics for carbon phenolic composites under tensile wave loading.

State Equation for an Advanced Ferromagnetic Base Composite Material

2013 ◽  
Vol 274 ◽  
pp. 451-454
Author(s):  
Guang Fa Gao ◽  
Shu Jie Yuan ◽  
Yong Chi Li ◽  
Ling Yan Shen
Keyword(s):  
Mechanical Properties ◽  
Shock Wave ◽  
High Pressure ◽  
Composite Material ◽  
Hot Spot ◽  
State Equation ◽  
Hugoniot Curve ◽  
Impact Compression ◽  
Gas Gun ◽  
Base Composite

Ferromagnetic base composite material is widely used in aerospace field, and its high pressure mechanical properties become the study hot spot in recently years. Aimed at an advanced ferromagnetic base composite material, its impact compression behaviors were investigated by means of Light Gas Gun (LGG). The shock wave velocity (D) and the particle velocity (u) behind the shock wave were measured and calculated by using Asymmetry Impact and Direct Measurement. Based on the experimental results and calculated results, a D-u type Hugoniot curve was obtained. The Grüneisen equation of state for the ferromagnetic base composite material and its coefficients were obtained on the basis of its Hugoniot curve.

Investigation into the Spall Strength of Cast Iron

2012 ◽  
Vol 13 (2) ◽  
pp. 195-199
Author(s):  
Gifford Plume ◽  
Carl-Ernst Rousseau
Keyword(s):  
Cast Iron ◽  
Spall Strength ◽  
Peak Stress ◽  
Small Scale ◽  
Spall Fracture ◽  
Gas Gun ◽  
Minimum Stress ◽  
Impact Experiments ◽  
Insight Into ◽  
Spall Failure

Abstract The spall strength of cast iron has been investigated by means of planar plate impact experiments conducted in a vacuum. A single stage gas gun was utilized to drive projectiles to velocities between 100 and 300 m/sec, resulting in low to moderate shock loading of the cast iron specimens. Measurement of the stress histories were made with the use of commercial manganin stress gauges that were imbedded between the back face of the cast iron specimen and a low impedance backing of polycarbonate. Spall strength values were calculated utilizing the measured peak stress and minimum stress pullback signals captured in the stress history. Spall Strength values were found to vary between 0.98 and 1.45 GPa for the cast iron tested. Post-Mortem analysis of recovered specimen has provided insight into the evolution of spall failure in cast iron and shed light on the varying nature of the spall strength values calculated. It was determined that the lower bound of strength values was associated with small scale micro-failure, while the upper bound values corresponded to complete spall fracture.

Histories of Geography

2016 ◽  
Author(s):  
Paul Stock
Keyword(s):  
Knowledge Acquisition ◽  
Physical Characteristics ◽  
Romantic Period ◽  
Political Events ◽  
The World ◽  
Geographical Study ◽  
History Of Geography ◽  
History Of ◽  
Whole Earth

This chapter discusses the history of geography during the Romantic period, concentrating on contemporary books which attempt to describe the whole earth and, in doing so, set out procedures for geographical study. Noting that ‘geography’ can refer both to the physical characteristics of the earth’s surface, and to the disciplined interpretation of those characteristics, the chapter begins by outlining the range of methodologies employed by these works. At the heart of geographical enquiry in the Romantic period are a set of significant epistemological questions about knowledge acquisition, and the perception and interpretation of the world. The chapter illustrates this by showing how two contemporary maps of Europe use different methods to justify and represent the limits of ‘European’ space. Furthermore, an understanding of geographical epistemologies—with their different assumptions about how to comprehend and intervene in the world—can help us interpret the tumultuous political events of the period.

Investigation into the Spall Strength of Cast Iron

2012 ◽  
Vol 13 (2) ◽  
Author(s):  
Gifford Plume ◽  
Carl-Ernst Rousseau
Keyword(s):  
Cast Iron ◽  
Spall Strength ◽  
Peak Stress ◽  
Small Scale ◽  
Spall Fracture ◽  
Gas Gun ◽  
Minimum Stress ◽  
Impact Experiments ◽  
Insight Into ◽  
Spall Failure

AbstractThe spall strength of cast iron has been investigated by means of planar plate impact experiments conducted in a vacuum. A single stage gas gun was utilized to drive projectiles to velocities between 100 and 300 m/sec, resulting in low to moderate shock loading of the cast iron specimens. Measurement of the stress histories were made with the use of commercial manganin stress gauges that were imbedded between the back face of the cast iron specimen and a low impedance backing of polycarbonate. Spall strength values were calculated utilizing the measured peak stress and minimum stress pullback signals captured in the stress history. Spall Strength values were found to vary between 0.98 and 1.45 GPa for the cast iron tested. Post-Mortem analysis of recovered specimen has provided insight into the evolution of spall failure in cast iron and shed light on the varying nature of the spall strength values calculated. It was determined that the lower bound of strength values was associated with small scale micro-failure, while the upper bound values corresponded to complete spall fracture.

scholarly journals Unsteady Effects During Resistance Tests on a Ship Model in a Towing Tank

2008 ◽  
Vol 52 (04) ◽  
pp. 263-273
Author(s):  
Lawrence J. Doctors ◽  
Alexander H. Day ◽  
David Clelland
Keyword(s):  
Wave Resistance ◽  
Excellent Correlation ◽  
Experiment Data ◽  
Towing Tank ◽  
Ship Model ◽  
History Of ◽  
Rate Of Decay ◽  
Unsteady Effects ◽  
Velocity History ◽  
Resistance Tests

It is known that there are oscillations in the wave resistance during the constant-velocity phase of a towing-tank resistance test on a ship model. In this work, the unsteady thin-ship resistance theory has been applied to this case. The results have been compared with experiment data obtained using a towing carriage the velocity history of which can be programmed. It is demonstrated here that generally excellent correlation exists between the theory and the experiments. In particular, one can predict the influence of Froude number, rate of acceleration, and type of smoothing of the acceleration on the characteristics of the oscillations. These characteristics include the amplitude, rate of decay, frequency, and phasing of the oscillations in the curve of wave resistance versus time.

Leadership Models

2021 ◽  
pp. 132-155
Keyword(s):  
Higher Education ◽  
Women Leaders ◽  
Hispanic Women ◽  
Physical Characteristics ◽  
Leadership Models ◽  
History Of

Leaders gain followers because they have various traits, concepts, and skills that appeal to followers. The history of leadership through the centuries has been dominated by men who have led because of their physical characteristics, personal charisma, fast wit, or their ability to relate to their followers. Do women have the same traits? Indeed! However, as the history briefly described and as this chapter will point out, it is primarily men who have been allowed to influence and impact their countries, communities, and institutions. Their leadership has, in fact, been based on and perpetuated by a hierarchical society where most women have not had a chance to control or even advance in the pre-established structures. Only a few Hispanic women/Latinas have been able to reach those positions and who should be proud of giving other women a glimpse into a way that they can break this cycle that has lasted for hundreds and thousands of years. These women leaders are now opening Hispanic women's and Latinas' pathways into higher education.

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