IFMASS10

261

CONTINUOUS MONITORING AND STRUCTURE INTEGRITY

ASSESSMENT

Nenad Gubeljak, Jožef Predan

University of Maribor, Faculty of Mechanical Engineering, Maribor, Slovenia,

Tomaž Valh, Drago Valh

Walch d.o.o., Maribor, Slovenia

1. INTRODUCTION

The Structural INTegrity Assessment Procedure (SINTAP) represents with its sequen-

tial approach an ideal basis for computer manipulation. The procedure might be seen as a

collection of recommendations mainly for engineering purposes in industry, for engineers

with practical experiences but limited knowledge of fracture mechanics. This application

provides a fracture assessment procedure useable as the basis of a structural integrity

management system. Several assessment levels are offered, from simple but conservative

approaches, with limited available data, to accurate and complex approaches.

Standard levels of SINTAP procedure are “Level 0”, “Level 1”, “Level 2”, “Level 3”.

When increasing the level, the demand for the entry parameters of the material increases.

There's also another issue, on which the application depends in addition to the standard

SINTAP procedure. This is the Engineering Treatment Model (ETM) method for asses-

sing the significance of crack-like defects in engineering praxis that offers the results of

the stress intensity factor and limit loading for different configurations. The application

already contains an example of lift car fork plus twelve loading configurations.

The main requirement when planning the application was the universality and

openness of the tool for manifold of elementary configurations in addition to already

included ones. One should also be able to export the results, data and graphs in standard

formats into other standard applications.

Though the SINTAP procedure is standardised, each solution holds for an individual

configuration, on the other hand. Its result in the simplest form is only information

whether is the identified damage in the construction safe or is there a potential danger for

a failure (fracture). This is basic information only. Consider that a crack can be safe for

the prescribed load but unsafe in case of overloading. The application enables repeating

the calculations with different properties of the crack or different loadings for that purpo-

ses. It remains up to the user to decide which is the critical parameter. In the context of

obtained results should be understood that the approaches described in this procedure are

not intended to supersede existing methods, particularly those based on workmanship.

They should be seen as complementary, the use of which should be aimed at ensuring

safe and efficient material's selection, structural design, operation and life extension.

1.1. Applicability

The procedure described is based on fracture mechanics principles and is applicable to

the assessment of metallic structures containing actual or postulated flaws. The purpose

of the procedure is to determine the significance, in terms of fracture and plastic collapse,

of flaws present in metallic structures and components.