W+B LFV-HH Electro-Hydraulic Servo Dynamic Fatigue Testing Machine

Overview

The W+B LFV-HH Electro-Hydraulic Servo Dynamic Fatigue Testing Machine is a high-capacity, precision-engineered structural testing system designed for full-scale static, quasi-static, and dynamic fatigue evaluation of materials, components, and civil or aerospace-grade assemblies. Built upon W+B’s century-long heritage in hydraulic servo technology—originating from the pioneering AMSLER engineering lineage—the LFV-HH integrates robust electro-hydraulic actuation with deterministic closed-loop control to deliver exceptional force fidelity, phase stability, and long-term repeatability under extreme loading conditions. Its core architecture employs dual-acting, equal-area servo actuators operating within a rigid reaction frame, enabling symmetric tensile and compressive loading up to 30,000 kN (3,061 metric tons-force) across a broad frequency spectrum (0.01–100 Hz). This makes the system uniquely suited for low-cycle fatigue (LCF), high-cycle fatigue (HCF), crack propagation (ΔK-controlled), fracture toughness (K_Ic, J-integral), creep–relaxation, and combined axial–torsional loading protocols per ASTM E606, E466, E647, ISO 1099, and EN 6072.

Key Features

• High-force electro-hydraulic servo actuation with integrated high-resolution displacement transducers (LVDTs) and load cells traceable to national metrology institutes
• Modular multi-actuator configuration supporting coordinated loading (up to 4 independent axes via PCS 200 T digital controller)
• Rigid, pre-stressed steel reaction frame with calibrated foundation interface—designed for installation on reinforced concrete mass foundations ≥1,500 tons
• Hydraulic power unit (PAC/PAR series) delivering up to 350 L/min flow at system-rated pressure; scalable for higher flow demands
• Force measurement certified to ISO 7500-1 Class 0.5 accuracy over full 0.2–2000 kN sub-actuator range; system-level calibration validated per ISO 376 and ISO 13385-1
• Real-time closed-loop control modes: force, displacement, strain, or hybrid (e.g., force–displacement cascade), with user-definable PID tuning and feedforward compensation
• Structural integrity verified through finite element analysis (FEA) and physical modal testing; fatigue life of main frame rated for ≥2 × 10⁷ cycles at 80% of maximum capacity

Sample Compatibility & Compliance

The LFV-HH accommodates specimens ranging from standardized coupons (ASTM E8, ISO 6892-1) to full-scale structural elements—including welded steel joints, composite airframe sections, railway bogie frames, wind turbine tower segments, and geotechnical soil–structure interaction models. It supports testing of metallic alloys (Ti-6Al-4V, Inconel 718), fiber-reinforced polymers (CFRP, GFRP), elastomeric bearings, asphalt pavements, timber laminates, and biomedical implants. All mechanical and software subsystems comply with ISO 17025-accredited calibration practices, and the integrated control system supports audit-ready data traceability aligned with FDA 21 CFR Part 11 requirements when configured with electronic signatures and secure user access tiers. The system meets EU Machinery Directive 2006/42/EC essential health and safety requirements and carries CE marking for industrial use.

Software & Data Management

Control and data acquisition are managed through W+B’s proprietary TestXpert II platform, a real-time deterministic OS-based application supporting synchronized sampling at up to 10 kHz per channel. The software provides standardized test templates for ASTM, ISO, and EN methods, along with customizable scripting (Python API) for non-standard protocols such as variable-amplitude spectral loading or thermomechanical coupling. Raw data streams include force, displacement, strain, actuator position, oil temperature, and pressure—all timestamped with microsecond resolution and stored in HDF5 format for interoperability with MATLAB, Python (NumPy/Pandas), and commercial FEA postprocessors. Audit trails log all parameter changes, operator actions, calibration events, and system errors—retained for ≥10 years per GLP/GMP archival policies. Remote diagnostics and firmware updates are supported via encrypted TLS 1.3 connections.

Applications

• Qualification testing of primary aircraft structures per DO-160 Section 8 and MIL-STD-810
• Fatigue life assessment of offshore wind turbine support structures under stochastic sea-state loading
• Fracture mechanics characterization of nuclear pressure vessel welds (ASME Section XI)
• Seismic performance validation of base-isolated bridge piers and energy-dissipating dampers
• Mechanical durability evaluation of orthopedic implant systems (ISO 14879-1, ASTM F2118)
• Creep rupture testing of high-temperature superalloys under sustained multiaxial stress states
• Development and validation of constitutive models for advanced composites used in hypersonic vehicle skins

FAQ

What is the typical lead time for delivery and commissioning of an LFV-HH system?
Standard delivery is 36–42 weeks from PO confirmation, inclusive of factory acceptance testing (FAT), site preparation review, and on-site SAT with W+B-certified engineers.
Does W+B provide traceable calibration documentation for the entire system?
Yes—each LFV-HH ships with a full ISO/IEC 17025-compliant calibration certificate covering force, displacement, and control loop performance, issued by W+B’s MLA-accredited calibration laboratory in Zurich.
Can the system be upgraded for future testing requirements (e.g., adding torsion or environmental chambers)?
All LFV-HH frames are designed with modular interfaces for retrofitting additional actuators, thermal shrouds (-70°C to +200°C), or acoustic emission sensors without structural modification.
Is remote support available for troubleshooting and software updates?
W+B offers 24/7 remote diagnostic access via secure VPN, with guaranteed response times under SLA: critical issues addressed within 2 hours, non-critical within 1 business day.
How does W+B ensure long-term parts availability for legacy systems?
W+B maintains a minimum 15-year spare parts inventory for all active platforms, including LFV-HH; custom machined components are retained in CAD format for on-demand manufacturing.