Structural Integrity

STRUCTURAL INTEGRITY

Investmech ensures structural integrity of machinery and structures applying experience, standards and mission profile driven requirements. In most cases analysed structure performance is confirmed by static and variable amplitude testing. Transient and quasi-static finite element analyses are done.

Operating torque limits

Applying a single- and multi-degree of freedom model for the drill string with reamer, the steady-state operating torque was calculated simulating mission profile driven structural inputs. Depth dependent make-up torque was calculated to prevent unwinding of drill strings after arrest of the reamer (exceeding the breakout torque). Trip limits were calculated to prevent exceeding specific breakout torques.

Vehicle structural integrity

Is ensured through mission profile driven finite element analysis and product testing. Acceleration and strain responses are reconstructed in the finite element analysis and durability testing.

Structural inputs

Investmech uses state of the art technology to ensure structural inputs are relevant.

Transient strain and acceleration responses of a headgear

Investmech measured strain and acceleration responses of a headgear during various mission profile driven operating conditions (trips, emergency stops, normal operation, etc.). These responses were used to predict axial, shear and bending moments on members and connections. From these, compliance with strength and fatigue requirements were confirmed. Results showed that on the structure below, thermal strains dominated the daily response.

Visual structural audits

Are done in detail to assess the condition of structural elements as well as connections to ensure the safe use of the structure.

Plant and building super structures

Plant and roof super structures are analysed using finite beam element analysis

Structural Dynamics

Investmech’s experience in structural dynamics cover the modelling and integrity assurance of super structures for ship, aeroplane, train, plant, incline conveyors, large material handling machine and the simulation of the transient dynamics of structures during demolition.

Shaft super structures

Calculation of structural inputs Testing and certification of new bolt joints Inspection and structural integrity audit Vibration measurement and operating deflection modes Deflection shape dependent condition-based maintenance based on MAC

Raise bore drill string structural integrity

Measured strains were used with a non-linear time and state dependent transient multi-degree of freedom mathematical model solved by the Runge-Kutta integration algorithm to find maximum and operating torque conditions. Start-up and post-stalling responses dominate design requirements.

Operating torque limits

Applying a single- and multi-degree of freedom model for the drill string with reamer, the steady-state operating torque was calculated simulating mission profile driven structural inputs. Depth dependent make-up torque was calculated to prevent unwinding of drill strings after arrest of the reamer (exceeding the breakout torque). Trip limits were calculated to prevent exceeding specific breakout torques.