Impulse Hammer WaveHitMAX

The invention of the first smart impact hammer provides new ways of mechanical excitation for structural dynamic applications. Smart means that the device processes its signals internally. The modal hammer WaveHitMAX guarantees fully automatic, reproducible and high-precision excitation of the test object without double hits. The user can set the number of hits, impact force and the delay between hits accounting for different degrees of damping / delay times. All presettings like zero point or impact force search are made automatically by the hammer. Manual adjustment by the user is no longer necessary.

WaveHitMAX has new features compared to semi-automatic impact hammers. The advantages of internal signal processing are:

  • Fully automatic single hits
  • Automatic search for user-defined impact force
  • Automatic zero point search
  • Validation of the impact for quality assurance
  • Change of the position between hammer and test object without new setup

The WaveHitMAX can be operated quickly and easily by the included software on a Windows enabled device (PC or tablet) through the Ethernet.

WaveHitMAX 
The First SMART Impulse Hammer

It is the tool of choice for:

  • Production
  • Modal testing
  • Acoustic resonance analysis

We guarantee a fully automatic, reproducible and highly precise excitation free of any bouncing and annoying parameter adjustments or tunings. This smart device called WaveHitMAX does these adjustments for you just automatically.

The user has several options to control the WaveHitMAX. Depending on whether he wants to operate it connected to a computer or completely autonomous, both is possible.

  • WaveHitMAX software for Windows 10 (64 Bit)
  • Integrated display with keypad
  • Wired trigger

There are four different tips for the hammer. The tips are made of different materials and have different hardnesses. They influence the excited frequency range accordingly. You can find the exact correlation on our technical page.

  • Metal (hard)
  • Plastic (medium)
  • Rubber (soft)
  • Rubber (extra soft)

There are also two different additional masses. These are used to apply additional force.

  • 12 g
  • 60 g

On the back panel of the WaveHitMAX are all necessary plugs and connectors. Among others:

  • M12 trigger input
  • BNC signal output
  • Ethernet connection

Depending on the excitation force, a different force sensor must be used. They cover different force ranges.

  • uniaxial with a maximum of 2.224 N and 2.25 mV/N
  • uniaxial with a maximum of 444 N and 11.2 mV/N

WaveHitMAX - The world's first SMART impulse hammer.

In this video, we are introducing the WaveHitMAX by gfai tech GmbH. The invention of the first smart impulse hammer provides new possibilities of mechanical excitation in structural dynamic applications. The WaveHitMAX guarantees a fully automatic, reproducible and high precision excitation of a test object without any double hits.

Benefits

  • Automatic zero point search
  • Reproducible single hit excitation
  • Internal sensor evaluation and process control
  • Automatic impact force search and adjustment
  • Changes in position are automatically anticipated
  • Configuration of the pulse properties by accessories
  • Trigger functionality via remote control or integration into the customer system
  • Designed and assembled in Germany. From the printed circuit board up to the final assembly
  • CE certified

Applications

  • Experimental modal analysis
  • Acoustic resonance testing
  • Condition monitoring
  • Material testing
  • Impact hammer testing
  • Frequency response function testing

System Integration

Software

Use the WaveHitMAX within your software. The WaveHit API (Application Programming Interface) for C++ helps you to integrate the full range of functions into your own application with little effort. A MATLAB® interface is coming soon.

Hardware

Use the WaveHitMAX together with your automation technology. The impulse hammer can be triggered directly via photoelectric sensors or controlled via programmable logic control.

Features

Smart

All presettings like zero point or impact force search are made automatically by the hammer. This makes it the first smart device of structural dynamics.

Single Hit

We guarantee a single hit excitation in almost all environments, positions and materials.

Automated

The WaveHitMAX finds its excitation point and its excitation force automatically.

Movable

If the test object is on a moving base like a production line or if it has simply been moved by accident, the WaveHitMAX can easily compensate for this.

Technical

For a correct excitation, the following must be ensured:

  • Excite the frequency range of interest with high amplitude (above the background noise of the sensor)
  • An amplitude uniformly distributed over the frequency range to be examined
  • Enough energy must be generated to excite the entire frequency range of interest, but not significantly beyond. The force must not drop more than 20 dB in the excited frequency range to get a sufficient energy input.
  • It must be ensured that enough force is induced into the structure to excite the modes of the structures.

A correct excitation should have the following course over the frequency range to be examined:

The general idea is that resonant frequencies can be more easily identified by applying the same force level over the entire frequency range.

The width of the input force is controlled by the duration of the shock pulse. However, the shorter the duration of the impulse, the wider the frequency range response.

To controll the input force frequency range, you can change the hammer tip in two ways:

  • Hammer mass – Reducing the mass of the hammer tip causes the hammer to touch the structure for a shorter time. Because the reduced mass allows the hammer to reverse direction more easily after hitting the structure, thus reducing the contact time.
  • Hammer tip stiffness – Increasing the stiffness of the tip also allows the hammer to shorten the time of contact. For example, a rubber tip could be replaced with a metal tip.

A hard tip has a very short pulse and excites a wide range of frequencies. Whereas a soft tip has a long pulse and excites a narrow frequency range. But the hammer tip itself does not completely determine the excited frequency range. The local flexibility of the structure must also be taken into account.

Generally applies: The lighter the hammer and the stiffer the tip, the higher the excited frequency range.

Choice of tips:

A double hit excitation can often be detected in the time domain as well as in the frequency domain.

If a second peak occurs in the time domain, this is an obvious evidence for a double hit excitation.

If this is not the case, it is possible that the second peak is just too small or too close to the first peak. In this case, the double hit excitation can be detected in the frequency domain.

It shows one of the following significant forms:

The effect of the double excitation can be calculated from the time interval between the two impacts.

The following chart shows how the inverse of the time interval affects the interference in the frequency band.

In Cooperation with:

Concept and technical implementation in cooperation with:
Ingenieurbüro Andreas Lemke

www.systementwicklung-lemke.de