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life-cycle cost modeling

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Series: ASM Handbook
Volume: 11A
Publisher: ASM International
Published: 30 August 2021
DOI: 10.31399/asm.hb.v11A.a0006802
EISBN: 978-1-62708-329-4
... Because of failures similar to those in Table 1 , predicting performance and assessing the remaining life with greater confidence becomes increasingly important as costs for manufacturers and operators need to be reduced. Furthermore, the cost of failure is progressively greater as systems become more...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003512
EISBN: 978-1-62708-180-1
... programs, enhanced analytical modeling and prediction techniques, accurate life assessment methods, and a fortified commitment to avoid the recurrence of these failures through improved designs. The examples cited in Table 1 were serious and often tragic failures that had a great impact on structural...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c0090114
EISBN: 978-1-62708-229-7
... to perform a life assessment. This case history demonstrates how that was done on a failed blade. Once the operating temperature and stresses are determined, then the life of blades with similar operating conditions can be determined. The first-stage blades in a model 501D5 gas turbine had 16 cooling holes...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003516
EISBN: 978-1-62708-180-1
... ( Ref 7 , 8 ), which has the form: ∑ i = 1 m n i N i = 1 provides a simplified approach to this problem. N i represents the total life of a component for a given stress cycle, n i represents the number of stress cycles actually sustained by the component...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003517
EISBN: 978-1-62708-180-1
... crack initiation or crack propagation or even total fatigue life. For fatigue crack initiation, the alternating stress ( S ) versus the number of cycles ( N ) to fail is typically represented by an S - N curve. For fatigue life, accounting for the elastic and plastic behavior, strain-life approach may...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003500
EISBN: 978-1-62708-180-1
... Lower life-cycle cost Reduced impact on the environment Some or all of these qualities at one time appeared mutually exclusive. However, customer demands and the aforementioned new business-management systems have provided a means of measuring and quantifying these attributes, creating a new...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006753
EISBN: 978-1-62708-295-2
... and users. These expectations include attributes such as: Greater safety Improved reliability Higher performance Greater efficiency Easier maintenance Lower life-cycle cost Reduced impact on the environment Some or all of these qualities at one time appeared mutually exclusive...
Series: ASM Handbook
Volume: 11A
Publisher: ASM International
Published: 30 August 2021
DOI: 10.31399/asm.hb.v11A.a0006819
EISBN: 978-1-62708-329-4
... or strain magnitude and the number of accumulated cycles are also required to carry out meaningful remaining life calculations ( Ref 3 ). This article is intended to offer an overview of fatigue fundamentals, common fatigue terminology, and examples of damage morphology (for different types of fatigue...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006792
EISBN: 978-1-62708-295-2
... affects a small volume of the material tested, and it often occurs over 10 8 cycles or more, which can represent tens of thousands of hours. The large number of cycles required means that life testing of bearings under standard operating conditions is generally considered cost-prohibitive. A number...
Series: ASM Handbook
Volume: 11A
Publisher: ASM International
Published: 30 August 2021
DOI: 10.31399/asm.hb.v11A.a0006800
EISBN: 978-1-62708-329-4
... materials, and selection and training of people ( Ref 3 ). Conceptual Design The first stage of design is to determine the physical concept by which the product will function. This includes the physical principles by which the product will work and an abstract physical model that will employ...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006868
EISBN: 978-1-62708-395-9
.... Processes that use lower pressure tend to have lower tooling costs but also tend to have longer cycle times; many have secondary trimming operations that will be required, adding to overall part cost. Lower-pressure processes tend to create scrap from trimming operations, some of which can be reprocessed...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001790
EISBN: 978-1-62708-241-9
...) . The region of initiation was not aligned with the shaft’s change of radius, as would be expected for a high-cycle fatigue failure if the fracture were related to design-induced stress concentrations. This observation suggests that the failure may not have been a simple end-of-fatigue-life incident that would...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003515
EISBN: 978-1-62708-180-1
... encountered damage mechanism ( Ref 8 ), and over time, two major design philosophies have been employed: safe-life (based on either stress versus life-cycle curves or strain versus life-cycle curves) ( Ref 9 ) and damage tolerant (based on fracture mechanics) ( Ref 9 , 10 , 11 ). Situations in which...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006921
EISBN: 978-1-62708-395-9
... information on the common aging mechanisms of polymeric materials and the common accelerated testing methods used to obtain relevant data that are used with the prediction models that enable service life assessment. Beginning with a discussion of what constitutes a product failure, this article then reviews...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003514
EISBN: 978-1-62708-180-1
...: Failure models continue to be enhanced for structural life prediction. Engineers realize that significant uncertainties and variations in loads, material properties, geometrical, and other parameters occur in real-world structures. A need exists to quantify the probability of failure of structural...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006909
EISBN: 978-1-62708-395-9
... for practical lengths of time (i.e., 6 to 12 months). Long-term service requirements, prohibitive testing costs, and the limited time available for product development, evaluation, and validation make accelerated life testing and aging necessary. Accelerated testing is carried out for several reasons: to assess...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006927
EISBN: 978-1-62708-395-9
... studied. End-Use Environment The end-use environment is a term used to describe the real-world conditions in which a plastic part is expected to function. It includes the operating temperatures, the chemicals the part will be exposed to, the expected life cycle of the part (days, months, years...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003501
EISBN: 978-1-62708-180-1
... are essential to proper service and cannot be subordinated, whereas secondary requirements are those where judicious compromises can be made. For example, life-cycle considerations (such as recycling or environmental impact) may be a primary or secondary criterion, depending on the product objectives...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c9001594
EISBN: 978-1-62708-229-7
...” failures. When a component fails after it has accumulated millions of cycles during its operating life, it is virtually certain that high-cycle, low-stress fatigue is the driving force. These fatigue cycles result from internal pressure pulsation, external vibrations, or a combination of both. Peak...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.steel.c9001149
EISBN: 978-1-62708-232-7
... Abstract A large diameter steel pipe reinforced by stiffening rings with saddle supports was subjected to thermal cycling as the system was started up, operated, and shut down. The pipe functioned as an emission control exhaust duct from a furnace and was designed originally using lengths...