Resonant Fatigue Testing Machines

Product Categories

Fatigue Tester - High Frequency Resonant Fatigue Testing Machine

Resonant fatigue testing machines generate dynamic cyclic loads by operating a specimen or component at the natural resonant frequency of the combined mechanical system — specimen stiffness, oscillating drive mass, and counter mass. At resonance, the energy input required to sustain the oscillation is minimal, because the system continuously stores and releases elastic potential energy like a mechanical pendulum. The drive unit needs only to compensate for energy losses due to internal damping, which is why resonant machines consume as little as 0.5 kW to 3 kW regardless of load capacity — compared to 10–50 kW for equivalent servo-hydraulic systems. This principle also means the machines are free of hydraulic actuators, valves, pumps, and oil circuits, so no ongoing maintenance is required for these wear-intensive components. The operating frequency automatically adjusts as specimen stiffness changes during crack propagation, following the system's natural frequency in real time and maintaining the target load amplitude through closed-loop control.

Qualitest offers four resonant fatigue machine platforms covering the full spectrum of laboratory and industrial fatigue testing requirements. The Cracktronic is a handheld-scale table model designed for pure dynamic bending applications, fracture mechanics precracking, and inline weld quality control — including nuclear hot-cell environments with optional manipulator operation. The mikroton serves loads up to 20 kN with axial tension/compression and covers the widest frequency range (40–250 Hz), making it the most compact and flexible solution for material S/N curve characterization and fracture mechanics research. The testronic scales the proven magnodyn electromagnetic resonant drive to 50–250 kN for mid-range structural and component fatigue testing. The vibrro-forte extends the same drive architecture to 700 kN for heavy civil and infrastructure applications — testing reinforcement steel bars, large fasteners, shafts, and structural joints — while weighing roughly half as much as comparable servo-hydraulic machines of equivalent capacity.

Applications in Industries

Aerospace & Defense

Fatigue life characterization of turbine blades, aircraft structural joints, fasteners, and composite panels. Fracture mechanics precracking for KᴵC and crack growth rate determination to ASTM E399, ASTM E647, and ISO 12108.

Automotive & Powertrain

S/N curve generation and endurance testing of connecting rods, crankshafts, valve springs, axle shafts, chassis welds, and suspension components. Supports automotive OEM and Tier-1 supplier qualification workflows.

Civil & Structural Engineering

Fatigue testing of reinforcement steel bars (rebars), prestressed strands, structural bolts, and welded connections per EN 1337, ISO 15835, ASTM A370, and ASTM E606. High-capacity vibrro-forte is purpose-built for long bar and fastener geometries.

Materials R&D & Academic Research

Generation of complete S/N Wöhler curves, fracture toughness KᴵC testing, da/dN crack propagation rates, K-threshold determination, and very high cycle fatigue (VHCF) investigation beyond 10⁸ cycles.

Nuclear & Energy

The Cracktronic's hot-cell compatible design with optional manipulator operation makes it suitable for fatigue and fracture mechanics testing of irradiated materials and nuclear structural components in controlled radiation environments.

Quality Control & Production Inspection

Inline and batch QC fatigue verification of welded joints, fasteners, cast parts, and machined components. The compact mikroton and Cracktronic are frequently deployed within production environments for statistical quality assurance.

Product Comparison Table

Specification / Feature	Cracktronic (Dynamic Bending)	Mikroton 5–20 kN	Testronic 50–250 kN	Vibrro-forte Up to 700 kN
Dynamic Drive System	Electromagnetic rotary oscillator	RUMUL mikroton (compact magnodyn-family)	RUMUL magnodyn (mid-capacity)	Dual magnodyn (high-capacity)
Load / Force Capacity	Max. bending moment: ±80 Nm dynamic; 100 Nm static	Up to 5 kN or 20 kN (dynamic peak)	50 kN, 100 kN or 250 kN (dynamic peak)	Up to 500 kN or 700 kN (dynamic peak)
Load Mode	Pure bending moment (R = −1 rotating beam)	Tension / compression (axial, R-ratio adjustable)	Tension / compression (axial, R-ratio adjustable)	Tension / compression (axial, R-ratio adjustable)
Frequency Range	40–250 Hz (5 adjustable steps)	40–250 Hz (4–5 adjustable steps)	40–160 Hz (8 adjustable mass steps)	50–160 Hz (specimen-stiffness dependent)
Dynamic Stroke	N/A (rotating bending)	±2 mm (typical)	±2 mm (typical)	Up to ±2 mm
Static Stroke	—	Ball-spindle servo; full range static adj.	Ball-spindle servo; up to rated static load	Ball-spindle servo; up to 600 mm displacement
Power Consumption	Low (resonant)	< 0.5 kW (resonant)	< 1.5 kW (typ.) (resonant)	< 3 kW magnet drive (resonant)
Machine Weight	65 kg (+ 25 kg control unit)	Approx. 30% of equiv. servo-hydraulic machine	Significantly lower than equiv. servo-hydraulic machine	Approx. 3,400 kg (half weight of equiv. servohydraulic)
T-Slotted Table	—	✓	✓	– (long-component design)
Special Foundation Req.	—	None (spring-mounted)	None (spring-mounted)	None required
Primary Applications	Fracture mechanics precracking; bending fatigue; weld QC; nuclear / hot-cell use	S/N curves; crack growth; K-threshold; QC testing; small specimens & components	S/N curves; crack growth; con-rods, fasteners, joints; R&D and QC	Large components: rebars, fasteners, shafts, crankshafts; infrastructure & civil engineering
Fracture Mechanics Tests	✓ (originally designed for)	✓	✓	✓
S/N Curve (Fatigue) Tests	✓	✓	✓	✓
Component / Assembly Testing	Limited (via modular concept)	✓ (T-slotted table)	✓ (T-slotted table)	✓ (purpose-built for long components)
Climatic Chamber Compatible	—	Optional	Optional	Optional
Nuclear / Hot-Cell Rated	✓ (optional manipulator)	—	—	—
PC / Software Control	✓ (RUMUL Software)	✓ (dual PC system)	✓ (RUMUL Software)	✓ (RUMUL Software)
Maintenance Required	None (resonant)	None (resonant)	None (resonant)	None (resonant)
Best For	Bending fatigue; fracture pre-cracking; nuclear / QC inline testing	Lab R&D; material screening; fracture mechanics; compact QC	Mid-force structural & component fatigue; automotive, aerospace, joining	Heavy civil / infrastructure fatigue; steel rebars, fasteners, large structural

* All machines self-follow resonant frequency during crack propagation. Static load adjustable during dynamic operation across full rated range. Climatic chamber, furnace, and environmental enclosure integration available as options on all axial models. Power supply requirements vary by model and configuration.

Why Choose Qualitest for Your Fatigue Testing Needs?

✔ Drastically Lower Operating Costs

Resonant fatigue machines consume as little as 0.5 kW (mikroton) to 3 kW (vibrro-forte) — a fraction of the power required by equivalent servo-hydraulic systems. No pumps, valves, oil cooling, or hydraulic power packs means dramatically lower running costs and eliminated consumable replacement schedules.

✔ No Maintenance Architecture

The resonant drive principle has no hydraulic actuators, seals, or valves to wear out. All four machines in the Qualitest fatigue lineup operate maintenance-free over their service life — protecting both your testing budget and your laboratory uptime.

✔ High Testing Throughput

Operating frequencies of 40–250 Hz compress S/N curve generation from weeks to hours. A full 10⁸-cycle fatigue test that would take over 115 days at 10 Hz is completed in under 12 hours at 250 Hz — a direct competitive advantage in development programs with tight timelines.

✔ Full Range Coverage in One Portfolio

From the handheld-scale Cracktronic for bending and fracture mechanics on small specimens, through the mikroton and testronic mid-range platforms, to the 700 kN vibrro-forte for heavy civil and infrastructure components — the complete resonant fatigue portfolio is available from a single supplier.

✔ No Special Foundation Required

Spring-mounted bases eliminate the need for reinforced concrete pads or pit installations, dramatically reducing installation cost and enabling rapid relocation. The mikroton's integrated controller further reduces lab footprint to a minimum.

✔ 26+ Years of Testing Expertise

Qualitest brings over 26 years of experience supplying precision testing instruments across 122+ countries, backed by application engineers who assist with machine selection, fixture design, test standard interpretation, and after-sale technical support.

Fatigue Testing at the Speed of Resonance

Whether your laboratory generates Wöhler S/N curves for material qualification, characterizes crack growth rates for fracture mechanics studies, verifies the fatigue life of automotive powertrain components, or confirms the structural integrity of civil infrastructure reinforcement bars, the Qualitest resonant fatigue platform has a machine matched to your load range, specimen geometry, and testing standard. With operating frequencies up to 250 Hz, power consumption up to 98% lower than servo-hydraulic equivalents, zero maintenance architecture, and no special foundation requirements, resonant fatigue testing is the most economical and efficient route to high-cycle fatigue data available today. Contact Qualitest to speak with a fatigue testing specialist, discuss your specimen geometry and target load range, and identify the right machine from our Cracktronic, mikroton, testronic, and vibrro-forte series — backed by over 26 years of precision testing instrumentation experience across 122+ countries.