Assessment of Ultrasonic Welds Using Pulsed Infrared Thermography

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Megan E. McGovern ◽  
Teresa J. Rinker ◽  
Ryan C. Sekol
Keyword(s):  
Automotive Industry ◽  
Source Distribution ◽  
Quality Inspection ◽  
Battery Cell ◽  
Pulsed Thermography ◽  
Electric Vehicle Battery ◽  
Temporal And Spatial ◽  
Heat Source Distribution ◽  
Metal Welding ◽  
Pulsed Infrared Thermography

Ultrasonic metal welding is used in the automotive industry for a wide variety of joining applications, including batteries and automotive wire harnessing. During electric vehicle battery pack assembly, the battery cell tab and busbar are ultrasonically welded. Quality inspection of these welds is important to ensure durable packs. A method for inspection of ultrasonic welds is proposed using pulsed infrared (IR) thermography in conjunction with electrical resistance measurements to assess the structural and electrical weld integrity. The heat source distribution (HSD) was calculated to obtain thermal images with high temporal and spatial resolution. All defective welds were readily identifiable using three postprocess analyses: pixel counting, gradient image, and knurl pattern assessment. A positive relationship between pixel count and mechanical strength was observed. The results demonstrate the potential of pulsed thermography for inline inspection to assess weld integrity.

scholarly journals Assessing Heavy Industrial Heat Source Distribution in China Using Real-Time VIIRS Active Fire/Hotspot Data

2018 ◽  
Vol 10 (12) ◽  
pp. 4419 ◽  
Author(s):  
Caihong Ma ◽  
Jin Yang ◽  
Fu Chen ◽  
Yan Ma ◽  
Jianbo Liu ◽  
...  
Keyword(s):  
Economic Development ◽  
Heat Source ◽  
Infrared Imaging ◽  
Mainland China ◽  
Processing System ◽  
Source Distribution ◽  
Heavy Industry ◽  
Rapid Urbanization ◽  
Active Fire ◽  
Heat Source Distribution

Rapid urbanization and economic development have led to the development of heavy industry and structural re-equalization in mainland China. This has resulted in scattered and disorderly layouts becoming prominent in the region. Furthermore, economic development has exacerbated pressures on regional resources and the environment and has threatened sustainable and coordinated development in the region. The NASA Land Science Investigator Processing System (Land-SIPS) Visible Infrared Imaging Radiometer (VIIRS) 375-m active fire product (VNP14IMG) was selected from the Fire Information for Resource Management System (FIRMS) to study the spatiotemporal patterns of heavy industry development. Furthermore, we employed an improved adaptive K-means algorithm to realize the spatial segmentation of long-order VNP14IMG and constructed heat source objects. Lastly, we used a threshold recognition model to identify heavy industry objects from normal heat source objects. Results suggest that the method is an accurate and effective way to monitor heat sources generated from heavy industry. Moreover, some conclusions about heavy industrial heat source distribution in mainland China at different scales were obtained. Those can be beneficial for policy-makers and heavy industry regulation.

Langjährige Be7 -Bodenluftmessungen lassen Änderung des atmosphärischen Austauschverhaltens während der letzten Jahrzehnte vermuten

1996 ◽  
Vol 51 (10-11) ◽  
pp. 1139-1143 ◽  
Author(s):  
S. Hartwig
Keyword(s):  
Exchange Process ◽  
Ground Level ◽  
Eddy Diffusivity ◽  
Source Distribution ◽  
Air Concentration ◽  
Minimum Concentration ◽  
Exchange Processes ◽  
Yearly Maximum ◽  
Heat Source Distribution ◽  
Ground Level Air

Abstract An analysis covering three decades (1964-1994) of monthly Be7 ground-level-air concentration measurements at Braunschweig shows a systematic trend of the data. This trend is related to the yearly maximum/minimum concentration ratio. The observation may be due to a continuous mitigation of exchange processes between stratosphere and troposphere. This finding is commensurate with the hypothesis that, due to the growing concentration of anthropogenic infrared active gases, the heat source distribution in the stratosphere and consequently the eddy diffusivity and exchange process between stratosphere and troposphere are altered. This results in a shorter irradiation period of stratospheric air portions by cosmic rays and consequently can lower the concentration of isotopes of stratospheric origin in ground level air.

Coupled-Physics Modeling of a Lithium-Ion Battery Cylindrical Cell Microstructure

2012 ◽  
Author(s):  
Peter N. Doval ◽  
Ilya V. Avdeev
Keyword(s):  
Cross Section ◽  
Automotive Industry ◽  
Hybrid Electric Vehicle ◽  
Emerging Market ◽  
Lithium Ion ◽  
Functional Materials ◽  
Battery Pack ◽  
Cylindrical Shape ◽  
Fe Model ◽  
Battery Cell

Safety of consumer vehicles is an extremely important consideration for the automotive industry. An emerging market in the automotive industry today is the electric and hybrid-electric vehicle market. As environmental concerns grow, such vehicles will become a necessity for manufacturers to remain within increasingly stringent emissions regulations. A recent problem with the high-voltage lithium-ion batteries used in many of these vehicles is that of thermal runaway following a severe collision. This paper represents our early attempt to look at one aspect of this extensive project — a coupled-physics model of battery cell microstructure. In this case, couple-physics refers only to thermal-structural coupling and the microstructure being studied here is the laminate-level structure. A 2-D finite element model of a lithium-ion cell was therefore developed. This 2-D model of the cell, also called a jellyroll, is a cross-section cut of one cell within a battery pack. Each battery cell is an assembly of alternating thin sheets of functional materials (anode, separator and cathode), which are rolled into a cylindrical shape. The cross-section then takes the form of a layered spiral. The typical cell is made of an aluminum cathode with coating, copper anode with coating, and a non-linear, viscoelastic polymer separator. Once the 2-D jellyroll FE model was created, some initial structural element simulations were run to validate the geometry setup and model integrity. Next, thermal-structural coupled-field simulations were run to investigate stress propagation resulting from thermal loads as well as the same loading cases performed with the structural-only model. Different loading conditions, including uniaxial stress-strain state, hydrostatic pressure test, and thermo-mechanical loading were simulated. The results from the simulations performed in the project set the groundwork of future models involving electrical properties and models of 3-D cells and the full battery pack.

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