Residual Stress in Automotive Powertrains: Methods and Analyses

2021 ◽  
Vol 1016 ◽  
pp. 1291-1298
Author(s):  
Dimitry Sediako ◽  
Joshua Stroh ◽  
Sina Kianfar
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Strain Gauge ◽  
Strain Analysis ◽  
Transportation Industry ◽  
Surface Measurements ◽  
Improved Performance ◽  
Active Research ◽  
Non Destructive ◽  
Reliable Methods

Residual stress is one of the main reasons for failure of automotive cylinder blocks and engine heads. These failures are typically associated with in-service distortion or cracking occurring in engines during operation cycles. The problem becomes more pronounced for engines that are running at elevated operating pressures and temperatures, limiting R&D options in developing and implementing higher-efficiency engines. New aluminum alloys and manufacturing methods have been introduced with varying degree of success, in many cases affected by the stress magnitudes and stress distribution in the component. Therefore, active research is ongoing internationally on finding the most reliable methods of stress analysis as a basis for developing efficient methods for stress mitigation. The current study presents a comparison between two experimental strain measurements techniques: a destructive method that is based on application of strain gauge sensors, and a non-destructive method using neutron diffraction. The results indicate that although the strain gauge method provides an indication of the nature (i.e. compression or tension) of strain within a component, this method should primarily be used for surface measurements and qualitative analyses only. Neutron diffraction remains the superior technique for strain analysis, particularly for engineering components with complex geometries. The results from this study provide the transportation industry with a more comprehensive understanding of the efficacy of utilizing strain gauge sensors, neutron diffraction or finite element modelling for measuring the residual strain in cast components. The results will help manufacturers to develop the next generation of powertrain systems with increased efficiency and improved performance.

Neutron Diffraction Evaluation of Residual Stress for Several Welding Arrangements and Comparison With Fitness-for-Purpose Assessments

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Anna M. Pardowska ◽  
John W. H. Price ◽  
Raafat Ibrahim ◽  
Trevor R. Finlayson
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Assessment Procedure ◽  
Stress Distributions ◽  
Fitness For Purpose ◽  
Single Bead ◽  
Surface Measurements ◽  
Number Of Passes ◽  
Neutron Diffraction Technique ◽  
Level 2

In this research, the neutron diffraction technique was used to investigate and compare the residual stress characteristics in several weld arrangements. This research has focused on the effects on residual stress of restraint condition applied during welding, the start and end of the weld for a single bead, and increasing the number of passes. The measured residual stress distributions are normalized by the yield strength of the material and compared with distribution provided in fitness-for-purpose procedures. It is found that the current safety assessment procedure BS 7910 and R6 Level 1 significantly conservative for longitudinal stresses outside the weld and heat affected zone, and for transverse residual stress across the weldment for surface measurements. For a less conservative assessment, R6 Level 2 is recommended, however, even if this assessment is often conservative, in particular, for transverse residual stresses.

Numerical Analysis of Welding Residual Stress and Its Verification Using Neutron Diffraction Measurement

1999 ◽  
Vol 122 (1) ◽  
pp. 98-103 ◽  
Author(s):  
Masahito Mochizuki ◽  
Makoto Hayashi ◽  
Toshio Hattori
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Surface Stress ◽  
Welded Joint ◽  
Strain Analysis ◽  
Evaluation Methods ◽  
Welding Residual Stress ◽  
Diffraction Measurement ◽  
Stress Distributions ◽  
Inherent Strain

Direct measurements and computed distributions of through-thickness residual stress in a pipe butt-welded joint and a pipe socket-welded joint are compared. The analytical evaluation methods used were inherent strain analysis and thermal elastic-plastic analysis. The experimental methods were neutron diffraction for the internal residual stress, and X-ray diffraction and strain-gauge measurement for the surface stress. The residual stress distributions determined using these methods agreed well with each other, both for internal stress and surface stress. The characteristics of the evaluation methods and the suitability of these methods for each particular welded object to be evaluated are discussed. [S0094-4289(00)01501-2]

Non-destructive magneto-strain analysis of YB2Cu3Oy superconducting magnets using neutron diffraction in the time-of-flight mode

2012 ◽  
Vol 112 (6) ◽  
pp. 063923
Author(s):  
M. Tomita ◽  
M. Muralidhar ◽  
K. Suzuki ◽  
A. Ishihara ◽  
Y. Fukumoto ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Superconducting Magnets ◽  
Time Of Flight ◽  
Strain Analysis ◽  
Flight Mode ◽  
Non Destructive

scholarly journals Non-Destructive Residual Stress Investigations of Natural Polycrystalline Diamonds

2014 ◽  
Vol 996 ◽  
pp. 969-974 ◽  
Author(s):  
Andrew M. Venter ◽  
Vladimir Luzin ◽  
Marco A.G. Andreoli ◽  
Sandra Piazolo ◽  
Tshegofatso Moipolai
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Environmental Contamination ◽  
Polycrystalline Diamond ◽  
X Ray ◽  
Diamond Phase ◽  
The World ◽  
Mechanisms Of Formation ◽  
Non Destructive ◽  
Stress Analyses

Three natural polycrystalline diamond samples have been investigated non-destructively in their raw as-discovered forms. The samples originate from different locations in the world and possibly have different mechanisms of formation. The study reveals that the stones are primarily composed of cubic diamond with varying amounts of impurities that emanate from their excessive porosities and entrapped environmental contamination from the areas they were formed and subsequently discovered. Residual stress analyses with X-ray and neutron diffraction techniques of the diamond phase in the interior regions of the diamonds revealed low stress values.

Investigation of Residual Stress Distribution of Wheel Rims Using Neutron Diffraction

2011 ◽  
Vol 681 ◽  
pp. 522-526 ◽  
Author(s):  
Marco Alessandroni ◽  
Anna Maria Paradowska ◽  
Enrico Perelli Cippo ◽  
Roberto Senesi ◽  
Carla Andreani ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Neutron Diffraction ◽  
Fatigue Cracks ◽  
Diffraction Method ◽  
Residual Stress Distribution ◽  
Hole Drilling ◽  
Wheel Rim ◽  
The Moment ◽  
Non Destructive

Damage accumulation due to fatigue significantly reduces the safety of railway vehicles. Shattered wheel rim failures are the result of large fatigue cracks that propagate roughly parallel to the wheel tread surface. The large stress, most likely due to wheel/rail impact or material discontinuity, is responsible for the initiation of shattered rims. The voids and inclusions of sufficient size in a stress field will also lead to failure of wheels. Significant improvements have been made in recent years to prevent the shattered rim failure. The ‘new’ wheels have a better resistance to the shattered rim failure, due to the fact that the circumferential residual stress on tread of a new wheel must be compressive to comply with requirements of international standard EN 13262. However, this may not necessarily apply for millions of ‘old’ wheels that are still currently in use. At the moment the residual stress measurements are carried out using destructive methods (such as slitting or hole drilling), or using quantitatively ultrasound method obtaining the average stress across the whole section. The main objective of this research was to apply non-destructive neutron diffraction method to quantitatively measure residual stress distribution of the wheel rim in as manufactured condition.

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