Development of Systems for Technical Training in the Field of Continuum Mechanics

"We successfully developed units for the qualitative and quantitative study of the mechanical properties of different materials used in industry by combining NI software (LabVIEW and Vision Acquisition Software) and hardware (multifunction DAQ devices)."

- César Bonilla, EDIBON, Chief Technical Officer

The Challenge:

EDIBON aimed to develop teaching units to support the learning of the principles, techniques, technologies, and applications in the areas of continuum mechanics and strength of materials, both at industrial and research levels.

The Solution:

EDIBON used NI technology to develop a family of units for the study of strength of materials, continuum mechanics, fracture mechanics, the theory of elasticity, and the theory of structures and biomechanics, as well as to determine the mechanical properties of the materials under study.

Author(s):


César Bonilla - EDIBON, Chief Technical Officer
Andrés Garro - EDIBON, Software Manager
Nuria Rafael - EDIBON, Mechanical Manager

 

EDIBON specializes in designing technical training equipment for several industries, including energymechanicsthermodynamicschemical engineering, and environmental. The mechanics field includes subareas such as mechanical engineeringautomotive engineeringcomputer-integrated manufacturingstrength of materialshydropneumatics and robotics, and more. Due to the growing research about industrial application materials, we are seeing increasingly complex techniques and test procedures in industries such as automotive, infrastructures, and manufacturing. For that reason, technicians and engineers need an up-to-date and adapted technical training that can help them understand the fundamentals on which those techniques are based.

 

 

In response to that demand, EDIBON has designed the EFO unit, applied to the strength of materials branch, and focused on the study of continuum mechanics through photoelasticity. This technique focuses on the analysis of stresses and strains, as well as their distribution and direction in systems subjected to external stresses. To that end, this unit includes a series of flat models made of materials with characteristic optical properties. When applying external loads, those properties make a series of isochromatic fringes visible on the models, whose formation pattern closely relates to the stress state experienced. Consequently, we can observe the stress distribution on the model at a glance and prove well known theoretical principles (Saint-Venant’s Principle, Navier’s Law, and more).

 

 

 

 

Likewise, the EFOC (Equipo de Fotoelasticidad con sistema de medida por galgas extensiométricas) and EFOV (Equipo de Fotoelasticidad con sistema de medida por galgas extensiométricas y sistema de visión artificial) units appear as variants of the EFO (Equipo de Fotoelasticidad) unit. The first one includes testing models equipped with strain gages that allow for determining the mechanical properties of the materials (Young’s modulus, Poisson’s ratio, and more). The second unit also includes a high-resolution camera for image acquisition and sensors to measure applied forces and strains. Thus, we can study the stress state of the tested models based both on the data acquired by the sensors and from the spectral analysis of the isochromatic and isocline lines observed in the images captured by the camera.

 

 

We can supply these units with a SCADA software developed with LabVIEW, as well as with high-performance and low-latency multifunction DAQ devices, such as the PCIe-6321. Thanks to these technologies, we can continuously measure the values of forces, stresses, and strains. We use the NI Vision Acquisition Software for image processing, accurately obtaining multiple results associated to the study of the isochromatic fringes shown in the models.

 

 

 

All the units include two additional software packages, an interactive computer-aided instruction (ICAI) software and ELK (Toolkit de Mecánica del Kit). We can use the ICAI software to perform practical exercises and tests with the units, assess users, obtain statistical results about their progress, and more.

 

We can use the ELK software development kit to get started with LabVIEW in a practical way having access to the source code of applications for these units and widening their functions. This results in customizable SCADA systems and helps users gain a better understanding and use of the units.

 

Results

We successfully developed units for the qualitative and quantitative study of the mechanical properties of different materials used in industry by combining NI software (LabVIEW and Vision Acquisition Software) and hardware (multifunction DAQ devices).

 

Author Information:

    
César Bonilla
EDIBON, Technical Director
C/ Del Agua, 14. Polígono San José de Valderas
Leganés 28918
Spain
Tel: +34-916199363
Fax: +34-916198647
edibon@edibon.com

Figure 1. EFO Unit With Flat Testing Model in Which Isochromatic Lines Can Be Observed as a Result of the Stress State in the Model
Figure 2. SCADA Software Obtains the Mechanical Properties From the Data Acquired (Young’s Modulus)
Figure 3. SCADA Software for the Spectral Analysis of the Isochromatic Fringes Observed in the Tested Models
Figure 4(a). Interactive Computer-Aided Instruction (ICAI) Software of the Mechanics Area
Figure 4(b). Mechanics Toolkit of the Software Development Kit Based on LabVIEW (ELK)