Main Menu

See All Software See All Instruments See All Transducers See All Vibration Testing Equipment See All Electroacoustics See All Acoustic End-of-Line Test Systems See All Academy See All Resource Center See All Applications See All Industries See All Services See All Support See All Our Business See All Our History See All Global Presence

Main Menu

See All nCode - Durability and Fatigue Analysis See All ReliaSoft - Reliability Analysis and Management See All Test Data Management See All DAQ Software See All Drivers & API See All Utility See All Vibration Control See All High Precision and Calibration Systems See All DAQ Systems See All S&V Hand-held Devices See All Industrial Electronics See All Power Analyzer See All S&V Signal Conditioner See All Acoustic Transducers See All Current and Voltage Sensors See All Displacement Sensors See All Force sensors See All Load Cells See All Multi Component Sensors See All Pressure See All Strain Sensors See All Strain Gauges See All Temperature Sensors See All Tilt Sensors See All Torque Sensors See All Vibration See All Accessories for Vibration Testing Equipment See All Vibration Controllers See All Measurement Exciters See All Modal Exciters See All Power Amplifiers See All LDS Shaker Systems See All Test Solutions See All Actuators See All Combustion Engines See All Durability See All eDrive See All Production Testing Sensors See All Transmission & Gearboxes See All Turbo Charger See All Training Courses See All Acoustics See All Asset & Process Monitoring See All Custom Sensors See All Data Acquisition & Analysis See All Durability & Fatigue See All Electric Power Testing See All NVH See All Reliability See All Smart Sensors See All Vibration See All Weighing See All Automotive & Ground Transportation See All Calibration See All Installation, Maintenance & Repair See All Support Brüel & Kjær See All Release Notes See All Compliance See All BKSV Worldwide Contacts

Main Menu

See All API See All Experimental Testing See All Piezoelectric Charge Accelerometers See All Piezoelectric CCLD (IEPE) accelerometers See All Electroacoustics See All Noise Source Identification See All Environmental Noise See All Sound Power and Sound Pressure See All Noise Certification See All Industrial Process Control See All Structural Health Monitoring See All Electrical Devices Testing See All Electrical Systems Testing See All Grid Testing See All High-Voltage Testing See All Vibration Testing with Electrodynamic Shakers See All Structural Dynamics See All Machine Analysis and Diagnostics See All Dynamic Weighing See All Vehicle Electrification See All Calibration Services for Transducers See All Calibration Services for Handheld Instruments See All Calibration Services for Instruments & DAQ See All On-Site Calibration See All Resources See All Software License Management

UPM: Concrete beams provide greater resistance to impact

The Structural Engineering Group at the UPM, Servosis, SPAIN


The Structural Engineering Group from the School of Civil Engineering at the Technical University of Madrid (UPM) has completed a project on analyzing the impact resistance in concrete, allowing them to follow up with a study on the behavior of protection structures when exposed to rock fall.

Headed by Professor Carlos Zanuy Sánchez, the Structural Engineering Group carried out impact tests on beams using a free fall machine in the sStructures lLaboratory. Developed by Servosis, the machine features piezoelectric force transducers with CFW load washers by HBK (CFW-190 and CFW-700), which are able to detect forces with the maximum precision possible. Reinforced concrete beams have a tendency to fail under shear load due to minimum energy absorption capacity during impact. Tests were therefore conducted to identify the improvement potential for resistance using beams with metal fiber reinforcement.


The Structural Engineering Group at the Technical University of Madrid (UPM) carries out a range of research projects in the field of structural engineering. One such project is its study on the resistance of reinforced concrete to impact (from rock fall). To conduct the study, the group needed the latest technology for measuring and recording forces and accelerations.

The Structures Laboratory (Laboratorio de Estructuras) at the Madrid University has installed a free fall machine developed by the company Servosis. This machine features type CFW piezoelectric force transducers manufactured by HBK (CFW-190 and CFW-700), and can detect forces with the maximum precision possible.

Tests Using a Free Fall Machine

The tests were performed on seven different types of concrete and three types of fiber: 0 percent (without fiber), 0.5 percent and 1 percent. Measuring 2,000 mm long and having a rectangular format (125 mm wide and 250 mm high), the beams were subjected to impact from a steel mass weighing 200 kg (with a radius of 29 mm at the point of contact), which was dropped from a height of 1.75 m at a speed of 5.9 m/s. The findings from the tests on the Servosis machine that was fitted with HBK testing and measuring equipment revealed that it is possible to prevent shear failure and improve safety depending on the type of fiber. The HBK transducers guaranteed the required precision when it came to recording impact and reaction forces, providing an accuracy of 4.3 pC/N. Piezoelectric accelerometers (PCB 353B14) with an accuracy of 5 mV/g2 were used to check vertical acceleration and the weight of the steel ball.

Customized Support

Servosis and the Structural Engineering Group opted for HBK due to the trust they have in HBK products and the support that its specialists provide when it comes to developing a solution which meets specific project requirements. As Joaquín Gonzalo, CEO and Technical Director at Servosis, stated during the construction process for the free fall machine:

“HBK has gained our trust thanks to its testing and measuring products and its cooperation in selecting the right products to achieve the best possible results.”

Precision and Reliability

HBK’s innovative products surpass the strict requirements regarding safety, reliability and quality to provide a versatile solution which is easy to install. The large piezoelectric rings with nominal forces of 190 and 700 kN are highly capable of withstanding overloads without losing accuracy or resolution. Experimental verification is essential for studying the response that structural elements give to impacts.

These transducers also feature added advantages as they come with a variety of accessories, load amplifiers, data acquisition systems, and measurement software – ideal if there is a need to create a complete measurement chain. After the notable success acquired by working together on this study, HBK and the UPM’s Structural Engineering Group intend to collaborate on other research projects in the future.

About The Structural Engineering Group at the UPM

The Structural Engineering Group at the UPM forms part of the Department of Continuum Mechanics and Structures at the School of Civil Engineering at the Technical University of Madrid (UPM). Besides teaching basic and advanced subjects in the structural engineering program at the School of Civil Engineering, the group also conducts research projects in the field of structural engineering. It also focuses on promoting structural engineering as a fundamental branch of civil engineering and provides a specialized service to both the public and private sector.

About Servosis

Founded in 1988, Servosis is a Spanish company which designs, develops and manufactures testing machines and electronic and mechanical systems used for quality control and analysis of materials, servo systems, machine and industrial process control, robots, measurement systems, and data acquisition.

INTERNAL USE - Case Study  UPM img4
Zanuy Sánchez.

Video of impact tests on beams 

Technology used