Mechanical shock. Testing machines. Characteristics and performance

2008 ◽  
Keyword(s):  
Mechanical Shock ◽  
Shock Testing ◽  
And Performance

scholarly journals Shock Pulse Shaping in a Small-Form Factor Velocity Amplifier

2010 ◽  
Vol 17 (6) ◽  
pp. 787-802 ◽  
Author(s):  
Gerard Kelly ◽  
Jeff Punch ◽  
Suresh Goyal ◽  
Michael Sheehy
Keyword(s):  
Pulse Shaping ◽  
Vertical Axis ◽  
Mechanical Shock ◽  
Practical Applications ◽  
Shock Testing ◽  
Acceleration Signal ◽  
High Acceleration ◽  
Component Assembly ◽  
Small Form Factor ◽  
Shock Pulses

This theme of this paper is the design and characterisation of a velocity amplifier (VAMP) machine for high-acceleration shock testing of micro-scale devices. The VAMP applies multiple sequential impacts to amplify velocity through a system of three progressively smaller masses constrained to move in the vertical axis. Repeatable, controlled, mechanical shock pulses are created through the metal-on-metal impact between pulse shaping test rods, which form part of the penultimate and ultimate masses. The objectives are to investigate the controllable parameters that affect the shock pulses induced on collision, namely; striker and incident test rod material; test rod length; pulse shaping mechanisms; and impact velocity. The optimum VAMP configuration was established as a 60 mm long titanium striker test rod and a 120 mm long titanium incident rod. This configuration exhibited an acceleration magnitude and a primary pulse duration range of 5,800–23,400 g and 28.0–44.0μs respectively. It was illustrated that the acceleration spectral content can be manipulated through control of the test rod material and length. This is critical in the context of practical applications, where it is postulated that the acceleration signal can be controlled to effectively excite specific components in a multi-component assembly affixed to the VAMP incident test rod.

scholarly journals Piezoelectric Energy Generators Based on Spring and Inertial Mass

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2163 ◽  
Author(s):  
Sanghyun Yoon ◽  
Jinhwan Kim ◽  
Kyung-Ho Cho ◽  
Young-Ho Ko ◽  
Sang-Kwon Lee ◽  
...  
Keyword(s):  
Piezoelectric Materials ◽  
Electric Energy ◽  
Inertial Mass ◽  
Design Parameters ◽  
Mechanical Shock ◽  
Generator System ◽  
Energy Harvesters ◽  
Shock Energy ◽  
Piezoelectric Energy ◽  
And Performance

In this study, inertial mass-based piezoelectric energy generators with and without a spring were designed and tested. This energy harvesting system is based on the shock absorber, which is widely used to protect humans or products from mechanical shock. Mechanical shock energies, which were applied to the energy absorber, were converted into electrical energies. To design the energy harvester, an inertial mass was introduced to focus the energy generating position. In addition, a spring was designed and tested to increase the energy generation time by absorbing the mechanical shock energy and releasing a decreased shock energy over a longer time. Both inertial mass and the spring are the key design parameters for energy harvesters as the piezoelectric materials, Pb(Mg1/3Nb2/3)O3-PbTiO3 piezoelectric ceramics were employed to store and convert the mechanical force into electric energy. In this research, we will discuss the design and performance of the energy generator system based on shock absorbers.

Designing Electronic Products to Withstand the Distribution Environment

1989 ◽  
Vol 111 (4) ◽  
pp. 294-298
Author(s):  
R. Peache ◽  
D. Privitera ◽  
J. Gasper ◽  
D. Heasty
Keyword(s):  
Mechanical Shock ◽  
Shock Testing ◽  
Design Cycle ◽  
Accepted Part ◽  
Shock Resistance ◽  
Product Modification ◽  
The Cost ◽  
And Storage ◽  
Sufficient Strength

During the past few years product mechanical shock fragility analysis has become an accepted part of the product design cycle at Wang Laboratories, Inc. This analysis is used to insure that the product has sufficient strength to work in the user environment without problem, and to survive the shipping environment from Wang to the customer without requiring excessively expensive shipping packaging. In some cases it is possible to make relatively inexpensive changes in the product which increase the mechanical shock resistance of that product. The cost of these changes is weighed against the cost of the amount of cushioning and related recurring costs needed in the shipping package to provide protection for the lower shock level the unmodified product is capable of withstanding. If the cost of product modification is lower than the cost of the increased package materials, freight and storage (increased cube), the modification is made to the product. A brief background of shock testing products is given, with particular attention to the use of ASTM D 3332. This process is presented as a specific case study on a recently developed CRT monitor.

scholarly journals Quasi-static and mechanical shock testing of reinforced shotcrete surface support

2017 ◽  
Author(s):  
Michael Raffaldi ◽  
Lewis Martin ◽  
Donovan Benton ◽  
Carl Sunderman ◽  
Michael Stepan ◽  
...  
Keyword(s):  
Mechanical Shock ◽  
Shock Testing

How Mitigation Techniques Affect Reliability Results for BGAs

2016 ◽  
Vol 2016 (DPC) ◽  
pp. 001992-002017
Author(s):  
Greg Caswell ◽  
Melissa Keener
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Operating Conditions ◽  
The Other ◽  
Lead Free ◽  
Mechanical Shock ◽  
Sinusoidal Vibration ◽  
Shock Testing ◽  
Mitigation Techniques ◽  
Lead Free Solders ◽  
Mitigation Technique

Since 2006 RoHS requirements have required lead free solders to take the place of tin-lead solders in electronics. The problem is that in some environments the lead free solders are less reliable than the older tin-lead solders. One of the ways to solve this problem is to corner stake, edge bond or underfill the components. When considering what mitigation technique and material to use, the operating conditions must be characterized. The temperature range is important when selecting a material to use since the glass transition temperature (Tg) and coefficient of thermal expansion (CTE) are important properties. If improperly chosen, the mitigation material can cause more failures than an unmitigated component. This study focused on 208 I/O BGAs on a 4 layer FR4 board. There were three solders tested; two lead free (SAC305 and SN100C) and one leaded (SnPb). Three mitigation techniques were tested: corner staking, edge bonding, and underfilling. Each of these techniques had two mitigation materials tested. One material was reworkable and the other was not. The boards were subjected to mechanical shock testing and sinusoidal vibration testing until failure. The results of the testing show that no one mitigation technique is best for all of the conditions tested. The same is true for the mitigation material. The best choice of mitigation technique and material is application dependent.

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