Single impact testing of suspension seats for high-speed craft

2017 ◽  
Vol 141 ◽  
pp. 116-124 ◽  
Author(s):  
Liam Gannon
Keyword(s):  
High Speed ◽  
Impact Testing ◽  
Single Impact

Correlating Drop Impact Simulations With Drop Impact Testing Using High-Speed Camera Measurements

2009 ◽  
Vol 131 (1) ◽  
Author(s):  
J. J. M. Zaal ◽  
W. D. van Driel ◽  
F. J. H. G. Kessels ◽  
G. Q. Zhang
Keyword(s):  
High Speed ◽  
Simulation Models ◽  
3D Models ◽  
Drop Impact ◽  
Impact Testing ◽  
Navigation Systems ◽  
High Speed Camera ◽  
Impact Performance ◽  
Impact Simulations ◽  
Board Level

The increased use of mobile appliances such as mobile phones and navigation systems in today’s society has resulted in an increase in reliability issues related to drop performance. Mobile appliances are dropped several times during their lifespan and the product is required to survive common drop accidents. A widely accepted method to assess the drop reliability of microelectronics on board-level is the drop impact test. This test has been standardized by international councils such as Joint Electron Device Engineering Council and is widely adopted throughout the industry. In this research the solder loading is investigated by combining high-speed camera measurements of several drop impact tests with verified finite element models. These simulation models are developed in order to gain an insight on the loading pattern of solder joints based on interconnect layout, drop conditions, and product specifications prior to physical prototyping. Deflections and frequencies during drop testing are measured using a high-speed camera setup. The high-speed camera experiments are performed on two levels: machine level (rebounds with and without a catcher) and product level (with different levels of energy and different pulse times). Parametric (dynamic and quasistatic) 3D models are developed to predict the drop impact performance. The experimental results are used to verify and enhance the simulation models, e.g., by tuning the damping parameters. As a result, the verified models can be used to determine the location of the critical solder joint and to obtain estimates of the solder lifetime performance.

Dynamic Analysis of Thin Glass Under Ball Drop Impact With New Metrics

2013 ◽  
Author(s):  
Liang Xue ◽  
Claire R. Coble ◽  
Hohyung Lee ◽  
Da Yu ◽  
Satish Chaparala ◽  
...  
Keyword(s):  
High Speed ◽  
Impact Testing ◽  
Image Correlation ◽  
Thin Glass ◽  
Fea Model ◽  
Wear And Tear ◽  
Local Measurements ◽  
Drop Impacts ◽  
Global And Local ◽  
The Impact

Response of brittle plate to impact loads has been the subject of many research studies [1–7]. Specifically, glass presents a wide variety of applications in daily life, and helps to protect the displays of smartphones, tablets, PCs, and TVs from everyday wear and tear. Therefore, the necessity of glass to resist scratches, drop impacts, and bumps from everyday use leads to the importance of investigation of the glass response under dynamic impact loading. The ball drop test has been applied in the past, specifying an energy threshold as a prediction metric. Use of energy as the key parameter in impact testing is limited, since it does not account for the time spent in contact during the impact event. This study attempts to establish a reliable metric for impact testing based on a momentum change threshold. The deformation and the strain of the glass will be obtained by the Digital Image Correlation (DIC) system, while the rebound velocity will be measured with the high speed cameras. The global and local measurements are conducted to verify the accuracy of the experimental results. Finally, the FEA model is developed using ANSYS/LS-DYNA to provide a comprehensive understanding of the dynamic response of the glass. Excellent correlation in deflection is obtained between the measurements and predictions.

Development and Evaluation of Silicon Nitride Components for Ceramic Gas Turbine

1998 ◽  
Author(s):  
Yasushi Hara ◽  
Katsura Matsubara ◽  
Ken-ichi Mizuno ◽  
Toru Shimamori ◽  
Hiro Yoshida
Keyword(s):  
Silicon Nitride ◽  
Gas Turbines ◽  
High Speed ◽  
Gas Flow ◽  
Impact Damage ◽  
Turbine Blades ◽  
Impact Testing ◽  
Particle Impact ◽  
Inlet Temperature ◽  
Power Turbine

NGK Spark Plug Co., Ltd. has been developing various silicon nitride materials, and the technology for fabricating components for ceramic gas turbines (CGT) using theses materials. We are supplying silicon nitride material components for the project to develop 300 kW class CGT for co-generation in Japan. EC-152 was developed for components that require high strength at high temperature, such as turbine blades and turbine nozzles. In order to adapt the increasing of the turbine inlet temperature (TIT) up to 1350 °C in accordance with the project goals, we developed two silicon nitride materials with further improved properties: ST-1 and ST-2. ST-1 has a higher strength than EC-152 and is suitable for first stage turbine blades and power turbine blades. ST-2 has higher oxidation resistance than EC-152 and is suitable for power turbine nozzles. On applying these silicon nitride ceramics to CGT engine, we evaluated various properties of silicon nitride materials considering the environment in CGT engine. Particle impact testing is one of those evaluations. Materials used in CGT engine are exposed in high speed gas flow, and impact damage of these materials is considered to be a concern. We tested ST-1 in the particle impact test. In this test, we observed fracture modes, and estimated the critical impact velocity. This paper summarizes the development of silicon nitride components, and the result of evaluations of these silicon nitride materials.

High and Low Speed Impact Characteristics of Nanocomposites

2015 ◽  
Vol 1105 ◽  
pp. 62-66 ◽  
Author(s):  
Saud Aldajah ◽  
Yousef Haik ◽  
Kamal Moustafa ◽  
Ammar Alomari
Keyword(s):  
High Speed ◽  
Impact Resistance ◽  
Absorption Capacity ◽  
Impact Testing ◽  
Energy Absorption Capacity ◽  
Low Speed ◽  
High Speed Impact ◽  
Bulletproof Vest ◽  
Impact Characteristics ◽  
The Impact

Nanocomposites attracted the attention of scientists due to their superior mechanical, thermal, chemical and electrical properties. This research studied the impact of adding carbon nanotubes (CNTs) to the woven Kevlar laminated composites on the high and low speed impact characteristics. Different percentages of CNTs were added to the woven Kevlar-Vinylester composite materials. An in-house developed drop weight testing apparatus was utilized for the low speed impact testing. Two different concentrations of the CNTs were added to a 15-layer woven Kevlar laminates, 0.32 wt% and 0.8 wt%. The results showed that: The 0.32 wt % CNT sample enhanced the interlaminar strength of the composite without enhancing the energy absorption capacity whereas, the 0.8 wt % CNT sample did not improve the impact resistance of the Kevlar composite.For the high speed impact tests, a bulletproof vest was prepared using woven Kevlar, resin, and CNTs at 1.5 w% percentage. The ballistic shooting was carried out by a professional shooter using a 30 caliber and 9 mm bullets for the tests. The CNT bulletproof sample bounced back the 30 caliber copper alloy bullet with no penetration.

Effects of modification on microstructure and properties of Al-bearing high-boron high-speed steel

2018 ◽  
Vol 116 (1) ◽  
pp. 108
Author(s):  
Zhang Yaguang ◽  
Hanguang Fu ◽  
Lin Jian ◽  
Wang Changan ◽  
Lei Yongping
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
High Speed Steel ◽  
High Hardness ◽  
Impact Testing ◽  
Wear Testing ◽  
Microstructure And Properties ◽  
Different Types ◽  
The Matrix ◽  
High Boron

The microstructure of Al-bearing high-boron high speed steel (AB-HSS) contains a large amount of borocarbides, which makes it have high hardness, superior wear resistance and thermal stability. But the borocarbides are coarser and continuously distribute along the grain boundary which seriously destroys the toughness of AB-HSS. In this paper, the microstructure and properties of AB-HSS were regulated by adding modifiers and quenching and tempering heat-treatment. The modifier was RE-Mg, Ti and N elements. The microstructure and properties of AB-HSS were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), the electron probe microanalysis (EPMA), hardness testing, wear testing, and impact testing. The results show that the borocarbides in as-cast AB-HSS are found in intergranular networks showing different degrees of continuity after adding different types of modifiers. The matrix of as-cast AB-HSS all is composed of ferrite, pearlite and martensite, and the borocarbides all consist of M2(B,C) and M7(C,B)3 after adding different types of modifiers. After high-temperature heat treatment, the borocarbides in the microstructure of RE-Mg modification AB-HSS appear as discontinuous networks showing signs of spheroidization and the distribution of the borocarbides is more uniform. The matrix of RE-Mg modification AB-HSS is martensite and the borocarbides consist of M2(B,C), M7(C,B)3 and M23(C,B)6. The hardness of RE-Mg modification AB-HSS reaches 61.7 HRC, and impact toughness increases by 52%, and has excellent comprehensive mechanical properties.

Vibration of High-speed Ship Frames

2013 ◽  
Vol 29 (03) ◽  
pp. 127-135
Author(s):  
Michael R. Davis ◽  
Gary Davidson ◽  
Timothy Roberts ◽  
Christopher Cato
Keyword(s):  
Rotor Blade ◽  
Strain Energy ◽  
High Speed ◽  
Beat Frequency ◽  
Impact Testing ◽  
Vibration Energy ◽  
Frequency Range ◽  
Pass Through ◽  
Two Sides ◽  
Structural Strain

Impact testing of a typical high-speed ship section has shown that the mode of vibration most likely to fall in the frequency range of excitation resulting from propeller or rotor blade passing is that where the ship frame rocks in a fore and aft direction about its base connection to the hull plate. This vibration has significant amplitude to either side of the keel and it is found that connection between the inboard and outboard sides is weak. As a consequence, vibration can occur in two modes in which the opposite sides of the hull either move together or in antiphase. This leads to the structural strain energy in the two modes being slightly different, the mode with rather less strain energy having slightly lower frequency. Because the frequencies of the two modes are close together, the transient response exhibits beating in which vibration energy is exchanged between the two sides of the hull at the low beat frequency. Vibration of the ship frames in this manner appears to have been the cause of minor weld cracking where the top of stiffeners pass through cutouts in the web of the ship frames within the fuel tank areas of the hull.

The Study of Blanking Frequency Effect on the Acceleration Performance of Impact Testing Machine Rotor

2014 ◽  
Vol 543-547 ◽  
pp. 150-153
Author(s):  
Yuan Bo Cai ◽  
Fang Zhao ◽  
Shi Jian Li ◽  
Na Zhao
Keyword(s):  
High Speed ◽  
Testing Machine ◽  
Impact Testing ◽  
Frequency Effect ◽  
Rotating Speed ◽  
Impact Testing Machine ◽  
Movement Characteristics ◽  
The Impact ◽  
Feed Inlet

This paper designed an impact testing machine to observe the movement characteristics of particles. We simulated the rotor with different blanking frequency and different rotating speed by EDEM to explore the acceleration of the rotor. Through simulation, blanking frequency could have an impact on the rotor acceleration of testing machine, and the greater Blanking frequency was, the more obvious hanging material phenomenon was. Increasing the diameter of feed inlet could ease the phenomenon of hanging material, but would decrease particles speed. Therefore, we should not only avoid the phenomenon of hanging material, but also make the particles get high speed when designing the impact testing machine.

Construction of Hammer for Sugarcane Shredder

2013 ◽  
Vol 811 ◽  
pp. 308-313 ◽  
Author(s):  
Pavel Podany ◽  
Jan Džugan ◽  
Josef Vacik
Keyword(s):  
Wear Resistance ◽  
Chemical Analysis ◽  
Dynamic Loading ◽  
High Speed ◽  
Impact Testing ◽  
Sugar Production ◽  
Weld Deposit ◽  
High Speed Impact ◽  
Microstructure Evaluation ◽  
Pin On Disc

Article deals with construction of hammer for cane shredder. Function of hammer in shredder consists in crushing sugarcane stalks for further processing in sugar production. Hammer loading and other calculations were made. Four weld deposit materials were suggested for protection of hammer against wear and dynamic loading. All samples with weld deposit were subjected to microstructure evaluation, chemical analysis, high speed impact testing and tribological PIN-on-DISC test for estimation of wear resistance. One weld deposit material was recommended as a result of these tests.

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