HOLISTIC STRUCTURAL INTEGRITY PROCESS




















ABOUT HOLSIP.COM

HOLSIP is based on the fundamental idea that failure modes or mechanisms are interconnected.  The idea that each failure mode/mechanism is a separate idea is useful but often does not deal with either mechanism overlap or interaction and reinforces the fragmentation so common in engineering.  In addition, HOLSIP is a physics based structural integrity design approach that is the underpinning of a reliability and integrity centered design system.  It is done in a systems framework that becomes the basis for design methods for monotonic, sustained, and cyclic loading of all structural load bearing members.  In addition, HOLSIP considers all fracture mechanisms for monotonic loading with consideration of the intrinsic nature of solids.  Other extrinsic issues considered are rates of loading, temperature, time of loading, chemical environments, wear and contact mechanics, and neutron and other forms of irradiation.  All time dependent and time related mechanisms of degradation involving the following are considered in HOLSIP:

  • Creep,

  • Environmental effects (corrosion of metals),

  • Fatigue,

  • Wear,

  • Combinations and Synergisms and Overlap of the above.

In addition to providing the focus for design systems and methods, HOLSIP provides the underpinning for failure analysis and retrospective design analysis.  Thus, it provides guidance to conducting CLOSED LOOP DESIGN with extensive use of failure analysis to guide CAUSE AND EFFECT ANALYSIS, failure modes effects analysis (FMEA), and fault tree analysis (FTA).  With emphasis on monotonic load application failure modes as well as time dependent and time related modes of failure the entire manufacturing use cycle of either a component/subsystem/system is considered.

HOLSIP is predicated both on the presence of Initial Discontinuity States (IDS) in materials/structures and that the IDS will respond to the energy fields provided by extrinsic factors, such as, forces, thermal environments, chemical environments, irradiation environments, contact stress fields, and other factors that provide energy to evolve the IDS.  When the evolution occurs this is referred to as an Evolving Discontinuity State (EDS).  In the event that the energy field is not applied or held at a steady state then the state of evolution of the discontinuities is frozen in time and now the material/structure is in a modified discontinuity state (MDS).  HOLSIP provide the analytical and experimental methods to make predictions/estimates of component overhaul/maintenance/inspection intervals.  The quantitative non-destructive inspection methods to assure structural integrity are integrated into the HOLSIP framework.  Issues of accessability, inspectability, and detectability are considered in taking into account the issue of detection of specific modes of degradation.  In addition, the HOLSIP framework considers whether the following can be specified within the desired risk criterion/a for assuring the desired level of structural integrity or reliability:

  • What to look for,

  • Where to look,

  • How to look,

  • When to look,

  • How often to look,

  • The NDI Method(s) detection threshold for the specific mechanism(s) of interest.

  • The Probability of Detection (POD) for the method of detection and mechanism of degradation.

Then entire HOLSIP framework should be adopted in the Professional Engineering Framework that assures the utilization of all concepts in accordance with the engineering structural integrity design state of the art (DSOTA).  This also requires that human integrity and ethical behavior will be followed at all stages of implementaton and utilization of HOLSIP concepts in accordance with the codes of ethics of Professional Engineering. 

 

Resume of David Hoeppner, P.E., PhD.

 

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