Technology Overview

Structural Health Monitoring / Management

CVM™ Overview

CVM™ offers a novel method for in-situ, real-time monitoring of crack initiation and/or propagation. CVM™ is a measure of the differential pressure between fine galleries containing a low vacuum alternating with galleries at atmosphere in a simple manifold. If no flaw is present, the vacuum will remain at a stable level. If a flaw develops, air will flow through the passage created from the atmosphere to the vacuum galleries. Sensors may either take the form of self-adhesive polymer sensors or may form part of the component. A transducer measures the fluid flow between the galleries.

CVM™ has been developed for use in both a laboratory environment or on operating equipment. The laboratory testing equipment has rapidly gained acceptance in testing facilities within the aviation industry; often used to control a fatigue testing program due to its proven reliability and built-in fail-safe properties. A portable unit is available to allow monitoring of components in operating equipment where access to critical components is difficult, time consuming and costly.

This product is capable of being integrated with an aircraft to provide an in-flight structural health monitoring system (SHM).  The In-flight structural health monitoring system developed using the CVM™ technology is able to continuously monitor the development of any cracks in predefined areas on an aircraft that are deemed to have a high risk of crack formation. The implementation of this technology will reduce the cost of mandatory structural integrity maintenance inspections, increase aircraft performance, and provide an increase in the safety of air travel.

In-flight SHM using CVM™ system produced by SMS will consist of a number of different types of sensors placed at strategic locations throughout an aircraft that are linked to onboard instrumentation to detect and report on the initiation and growth of cracks.

CVM™ Competitive Advantages

The fundamental simplicity of the CVM™ technology provides a unique set of competitive advantages and great flexibility in the design and application of structural monitoring systems. CVM™ systems:

  • are simple to install, lightweight and inert with long term durability;
  • can be implemented in a range of sensor types and configurations to address structural fatigue and structural integrity health monitoring requirements;
  • installed in hard to access areas can be periodically inspected via a remote access point in a matter of minutes, enabling a major reduction in maintenance inspection costs and improvements in aircraft operational availability;
  • fluidic sensors are made from radar transparent materials that do not generate electromagnetic or acoustic emissions;
  • can detect and monitor cracks by direct measurement of pressure changes avoiding the complicated   processing of complex sensor outputs currently used in existing inspection techniques;