Non-Destructive Inspections: Bercella & Vetorix
Non-Destructive Inspections (NDI) are non-invasive techniques, used in order to assess the integrity and absence of defects in the component, without damaging it. This is especially true for the world of composites, as the parts are made of laminated prepreg skins, and it is therefore crucial to verify that there are no occlusions or other defects within the layering or the prepreg itself, which would not be externally detectable. The purpose of non-destructive testing is to issue an acceptance / rejection judgment of a material or component, depending on whether or not it meets the initial design and quality requirements.
Let’s find out more with Luca Limena, General Manager at Vetorix Engineering.
How many years have you been collaborating with Bercella? Is there a virtuous circle in the relationship between the two companies?
Indeed, several years have passed and it is a pleasure to see that both companies have made a good path of growth and increase in value both from a technological and a market point of view. The first contacts with Franco date back to almost fifteen years ago and the first issue we faced together was not the simplest one. It was a foreign customer who needed the designing and manufacturing of a large and “prototype” structure.
As far as the NDI part was concerned, there were no precise indications or technical specifications of reference; therefore, together with the Engineering and Quality department, we were able to set up a control process that covered 100% of the surfaces of the component with affordable time and costs. In the end, the determination and professionalism of both of us, led to customer satisfaction, which is one of the basic principles of our work. As a last note, just last year we were commissioned an inspection by that same customer for two components similar to the original ones, and with satisfaction we have replicated the same inspection process, which I can say “didn’t aged at all”.
The NDIs allow you to inspect a finished component, immediately before it performs the task for which it was designed and built. What are the advantages in terms of time and cost savings?
The purpose of the NDI is precisely to detect any imperfections of the component under test without having to damage it. Evaluating the effectiveness of one survey technique compared to another is not easy and often this evaluation is linked to the operating context, the type of component to be inspected, the type of expected defects and many other variables. The examination of composite material structures is not very regulated, so experience and technology are two key elements to consider when choosing the best approach to any inspection.
Entering the merits, I believe that for composites, combining at least two examination techniques is a good strategy; Vetorix, for example, has been using a combination of thermography and ultrasound for years. In fact, active thermography is very effective for the inspection of carbon components even with complex geometry as it has excellent sensitivity near the surface, which however decays with increasing thickness, and is also advantageous as it is very fast in execution.
Ultrasound, on the other hand, guarantees an excellent detection capacity even for in-depth defects but requires an appropriate probe-surface coupling which on certain pieces is not easy to obtain; in addition it requires excellent experience on the part of the technician who has to interpret the echograms. Although it requires a lot of care, it is the best known and most used examination technique from the racing sector to aerospace.
However, if I have to choose one, the first place certainly goes to Tomography which represents an excellent compromise of precision between data acquisition and practicality in scanning. Unfortunately, today it is a very expensive type of test and is intended for the inspection of small components, but I am confident that there will be interesting developments in the near future.
Bercella has been manufacturing carbon fiber for Italian and foreign customers for twenty-five years, and Vetorix has been on the national and international market for more than thirty. What does the fact of working with a company with so much experience mean to you?
Experience, innovation… I believe they are the key to success. The longevity of a company but also of a single project is often measured with the creation of Value, which is in fact a very difficult process that must remain in perfect balance in customer-supplier relationships and which above all depends on the internal dynamics of each company.
The drive for innovation, as well as consolidation and organization, are fundamental elements for the creation of value, which must be perceived from the outside and must be created from the inside; a difficult task for both the entrepreneur and the collaborators.
I believe this is the main characteristic that unites companies like Vetorix and Bercella and I think this is what keeps us alive over the years. Then yes, it is true that with the experience that gradually matures, the perception of the market and the context can change, but I think the basic values remain the same and are the cornerstone of growth. I think the Vetorix-Bercella axis has always stood out for its professionalism and innovation, and I can say with good certainty that if we have survived the various crises and conjunctures of recent years … well, nothing scares us!
On which projects or on which sectors do you mainly work with Bercella?
In recent years, Bercella has grown a lot in the aerospace sector and this sector requires systematic NDI checks. The interesting thing is that the Space structures are uniques in the sense that they present different problems and are produced in very limited numbers. It follows a considerable effort for the development of the NDI process, which often has to be customized and subsequently applied on very few specimens. It has sometimes happened that an entire test campaign on various samples is aimed at setting up an NDI process for the inspection of a single “flight” component!
This makes us understand how the preparation of the process and the care in carrying out the tests must be almost maniacal, without counting the attention in the realization of the product itself. I remember, for example, that at the end of 2017, the Bercella team showed up with the “drill box” project for the Exomars mission rover (2022) and a few months later with the first prototype. We decided to develop a combined inspection process that included ultrasound and tomographic tests, but the Drill Box was so “innovative and unique”, so much was our STG tomography system (inaugurated a few months earlier).
I believe that if on this and other occasions I hadn’t had the good fortune to work with smart and competent guys like the Bercella engineers, it would surely have turned out a mess. To be honest what has always impressed me is their problem-solving skills. In fact, it often happens that during the NDI tests defects in the material or problems of various kinds are detected, and when working on very particular structures and often without reference standards, it becomes very complicated to solve the problems. With Bercella, on the other hand, it is almost pleasant to face these situations, since they demonstrate a critical, technical sense and an ability to analyze clearly above the average. This method, in my opinion, creates value, that value that is not found everywhere, that value that allows you to evolve rather than capitulate when facing problems.
Bercella counts Aerospace among its main fields of application, and in the coming years it will become a more and more prominent player of the Space Valley. What does this “space” challenge represent for you? Do you need different tools to analyze and approve these types of components?
I am sure Bercella will increasingly be a reference player in the national aerospace context and beyond. As for the upcoming challenges, whether in the aerospace field or not, I believe that the decisive element is the nature of our collaboration which, in addition to the professional side, has strong “human” synergies consolidated over the years, which often characterizes long-lasting collaborative relationships. What is certain is the commitment that I will put in first person to develop increasingly innovative and effective inspection systems, in order to remain an important link in the Bercella value chain.
For example, the STG computed axial tomography system was designed with the needs of some customers who needed a faster and more versatile tomography system. Although the first prototype of the STG system was developed 8 years ago, I believe that the parable of its development is still in a phase of strong growth and the best suggestions for this development come from customers. Generally, the stimulus deriving from the technical challenges that my customers present to me every day is the best “fuel” for innovation, which Vetorix is happy to put to good use with stimulating partners such as Bercella.