Failure pattern

The expected life is sometimes used as an iadicator of system rehabihty however, it can be a false iadication and should be used with caution. In most test situations the chance of surviving the expected life is not 50% and depends on the undedyiag failure pattern. For example, considering the exponential as used ia equation 10, the expected life would be... 

The Nonzero Minimum-Life Case. In many situations, no failures are observed during an initial period of time. For example, when testing engine bearings for fatigue life no failures are expected for a long initial period. Some corrosion processes also have this characteristic. In the foUowing it is assumed that the failure pattern can be reasonably weU approximated by an exponential distribution. 

Evidence that indicates a failure pattern that may correlate with maintenance activities. 

Failure pattern analysis of the C ALGB and French trials showed that local persistence or failure still occurred in around 80% of patients despite the ChT however, the incidence of distant metastases as a first site of failure was significantly lower in the combined modality group, confirming the theoretical potential that ChT could effect distant micrometastases. Subsequent meta-analyses confirmed the superiority of induction ChT, using a cisplatin-based regimen, and RT over radiation alone (60,65). Thus, sufficient evidence was now in place to establish induction chemoradiation as a world-wide standard of care. To further improve outcome, steps would have to be taken to improve local disease control as well. 

Komaki R, Scott CB, Byhardt RW, et al. Failure patterns by prognostic group determined by recursive partitioning analysis (RPA) of 1,547 patients on four Radiation Therapy Oncology Group studies in inoperable non-small cell lung cancer (NSCLC). Int J Radiat Oncol Biol Phys 1998 42 263-267. 

Fig. 35 a Failure pattern in the neat polysulfide adhesive sample PSCO. b Failure pattern in clay-loaded sample PSC8... 

Typical failure pattern with fracture transverse to the machine direction. 

There are numerous techniques known for adhesion and delamination testing, some of the most common being a tape test, stud-pull test, scratch test, and an indentation test [1]. In the tape test, a tape is pulled off the surface containing a scratch, which provides the failure initiation. In the stud pull test, a stud held with thermosetting epoxy is pulled off the film surface. The indentation test, wherein a ball is pressed into the surface, is used for hard coatings, and the failure pattern indicates acceptable behavior. In the scratch test, where an indenter moves in both vertical (loading) and horizontal (sliding) directions, an acoustic emission sensor allows for detection of the initiation of fiacture, while the scratch pattern indicates the type of failure. 

Extensive studies on failure patterns to improve maintenance strategies and operational procedures identified six basic patterns. 

According to the overlying rock breaking process and failure pattern of the fully mechanized gob-side entry retaining, numerical simulation concluded Through the orthogonal test method to the main roof fracture factors influence, a numerical simulation to get the order main roof thickness >... 

Spectral analysis of the limited OMS units that have been deployed has been nsed for gaining knowledge regarding OMS time to failure pattern. Figs. 2 and 3 show the spectral analysis for an OMS when it was installed and 20 months later, respectively. 

The relationship between the conditional probability of failure of an item and its age. Failure patterns are generally applied to failure modes. Research in the airline industry established that there are six distinct failure patterns. The type of failure pattern that applies to any given failure mode is of vital importance in determining the most appropriate equipment maintenance strategy. This fact is one of the key principles underlying Reliability-Centered Maintenance. 

Sura S, Greco C, Gelblum D, Yorke ED, Jackson A, Rosenzweig KE (2008) (18)F-fluorodeoxyglucose positron emission tomography-based assessment of local failure patterns in non-small-cell lung cancer treated with definitive radiotherapy. Int J Radiat Oncol Biol Phys 70 1397-1402... 

A 1.5-tonne steel slab pendulum is suspended by a chain and allowed to fall and strike the front of the cab - a frontal impact of 4500 mkgf. This test evaluates mainly the strength of the steel cage (ECE Regulation No. 29) but strain gauges are also fitted to the SMC panels to observe failure patterns. 

Deformation and failure pattern of cohesive slopes reinforced with different materials Centrifuge modeling study... 

This paper addresses a series of tests on reinforced cohesive soil slope, measuring the displacement of soil by the image analysis system developed by Zhang et al. (2009). The failure pattern of each slope is depicted. Such factors as spacing of reinforcement layers, the tensile modulus of the reinforcement, and the interface between the reinforcement and the soil are studied and their influence on the reinforced slopes is discussed. 

Figure 2. Failure pattern of the unreinforced slope of Model N-1 at 100 g (in cm).

It was found from the failure pattern that the unreinforced slope was prone to collapse suddenly, while reinforced slopes were able to maintain their integrities. As far as the reinforced slope is concerned, cracks mainly occurred in three places (1) the zone near the surface, from toe to half of the slope (2) top of the slope and (3) the interface between each layer of reinforcement and the soil. The cracks occurred first near the slope surface. The cracks on top of the slope were mainly tension cracks. The largest crack on the top mainly located in the unreinforced region. In the reinforced... 

Figure 10. Effect of orientation of bedding planes on the uniaxial compressive strength of heterogeneous rocks. Failure pattern is at different orientations is shown.

The loess covers an area of 635,300 km (6.63% of the total land area) in China (Yan et al., 2011), which mostly distributes in high earthquake intensity zones, so it is important to understand the dynamic response and earthquake-induced failure patterns of the loess slope. This kind of research, however, has mostly been done in China (Wang et al., 1999, Wang et al., 2001, Gu et al., 2009) and many problems of this field remain unsolved. 

Changshougou loess slope in Baoji City is chosen as an analyzing example. A three-dimensional model of the slope and its physical and mechanical parameters are obtained according to the geotechnical condition of the slope and micro-tremor in situ testing result. The finite-difference software FLAC is adopted to simulate the dynamic response and failure patterns of the slope to the excitation of vertically incident shear waves with different vibrating directions and intensities. 

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