Photovoltaic (PV) modules. Cyclic (dynamic) mechanical load testing

2016 ◽  
Keyword(s):  
Mechanical Load ◽  
Load Testing ◽  
Dynamic Mechanical ◽  
Pv Modules ◽  
Cyclic Dynamic

NMR imaging of technical SBR vulcanizates under dynamic mechanical load

1997 ◽  
Vol 198 (9) ◽  
pp. 2729-2742 ◽  
Author(s):  
Daniela Hauck ◽  
Peter Blümler ◽  
Bernhard Blümich
Keyword(s):  
Mechanical Load ◽  
Nmr Imaging ◽  
Dynamic Mechanical

Development of Surrogate Biomedical Knee Implants for Validation of Embedded Smart Sensors

2017 ◽  
Author(s):  
Robert I. Ponder ◽  
Mohsen Safaei ◽  
Steven R. Anton
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Mechanical Load ◽  
The United States ◽  
Cnc Machining ◽  
Load Testing ◽  
Common Procedure ◽  
Biomedical Sensors ◽  
Fused Deposition ◽  
Medical Grade

Total Knee Replacement (TKR) is a very common procedure in the United States, especially with the aging population. However, despite high numbers of procedures and advancing technology, about 20% of patients with TKR are unsatisfied with the level of discomfort they experience with their replacement. Prevailing theories suggest that this is due to gradual misalignment of the knee. Multiple methods have been attempted to detect the cause of mechanical failure in replacements. One possible method for performing state detection in knees is the embedding of piezoelectric transducers (PZTs) into the bearing component. Preliminary testing of PZT’s embedded in simplified plastic components has shown that this method contains promise. With this said, further testing on realistic knee implant components is still needed to solidify the method’s validity. Commercial knee implant bearings utilize medical grade Ultra-High Molecular Weight Polyethylene (UHMW) and manufacturers utilize proprietary processing technology to develop the final components. This work focuses on the development of surrogate knee implant prototypes that replicate the material and geometric properties of actual knee implants to provide a convenient and economical solution to evaluate the performance of embedded PZTs. In this work, scans of an original knee bearing are taken and used to create a 3D model. From there, a variety of processes including 3D printing and Computer Numerical Controlled (CNC) machining are used to develop surrogate prototypes that are compared for accuracy to a benchmark. This benchmark is taken as a polished CNC machined non-medical grade UHMW prototype. Standards that the prototypes must meet include cost and time effectiveness as well as similarity in geometry and material property to the benchmark. The performance of the prototypes is experimentally compared through mechanical load testing by using pressure sensitive films placed between the femoral and bearing components of the implant as well as measuring piezoelectric output. In addition, the measured voltage output is compared to predictions from an analytical model for validation of the piezoelectric performance. These two experiments help to derive information about the applied load distribution and location, allowing comparisons to be made to the benchmark. This study shows that, while some types of 3D printing, such as fused deposition modeling, provide fast and cheap prototypes, other options such as stereolithography printing produce higher quality and more replicative components. Results of this study can be used in the development of useful surrogates for the advancement of biomedical sensors.

Dynamic mechanical load emulation test facility to evaluate the performance of AC inverters

2000 ◽  
Vol 14 (1) ◽  
pp. 21-28 ◽  
Author(s):  
C.R. Hewson ◽  
P.W. Wheeler ◽  
G.M. Asher ◽  
M. Sumner
Keyword(s):  
Mechanical Load ◽  
Test Facility ◽  
Dynamic Mechanical

Measurement and simulation of vibrations of PV-modules induced by dynamic mechanical loads

2011 ◽  
Vol 19 (6) ◽  
pp. 688-694 ◽  
Author(s):  
Marcus Assmus ◽  
Steffen Jack ◽  
Karl-Anders Weiss ◽  
Michael Koehl
Keyword(s):  
Mechanical Loads ◽  
Dynamic Mechanical ◽  
Pv Modules

scholarly journals Optimizing Viscoelastic Properties of Rubber Compounds for Ballistic Applications

2020 ◽  
Vol 10 (21) ◽  
pp. 7840
Author(s):  
Janis Karl ◽  
Franziska Kirsch ◽  
Norbert Faderl ◽  
Leonhard Perko ◽  
Teresa Fras
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Mechanical Stress ◽  
Mechanical Load ◽  
Superposition Principle ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Ballistic Impact ◽  
Dynamic Mechanical

Using interlayers of rubber adds a positive effect to the synergy of disruptor–absorber armors. Emerging from its viscoelasticity the material is able to transform mechanical stress into heat. The dynamic mechanical properties of elastomers depend on both ambient temperature and frequency of an applied mechanical load. The damping shows a maximum in the glass transition area. If the frequency of the glass transition is in the magnitude of the mechanical stress rate applied by ballistic impact, the elastomer will undergo the transition and thus show maximized damping. An ideal material for ballistic protection against small calibers is developed by making use of dynamic mechanical analysis and the time–temperature superposition principle. The material is later analyzed by ballistic experiments and compared to other nonideal rubbers with regard to glass transition temperature, hardness and damping. It is shown that by choosing a material correctly with certain glass transition temperature and hardness, the ballistic properties of a steel–rubber–aluminum armor can be enhanced. The chosen material (butyl rubber) with a hardness of 50 °ShA is able to enhance energy absorption during ballistic impact by around 8%, which is twice as good as other rubber with non-optimized properties.

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