tructural Testing of Stress and Fatigue tructural Testing of Stress and Fatigue | HBM

Structural Durability and Fatigue Testing

Structural integrity is highly significant for a vehicle’s life expectancy – how is the vehicle’s integrity in terms of body construction, chassis or other components such as damping, axles, powertrain mounts or entire assemblies? How do environmental conditions such as temperature, humidity and sunlight impact the vehicle’s structural integrity? The following parameters should be balanced:

  • Optimal weight and dimensioning of the overall construction
  • Safe operation
  • Durability
  • Robustness
  • Performance
  • Reliability

 

During testing, a vehicle has to withstand typical mechanical loads encountered in operation over a specified simulated lifetime. Failure in the form of fatigue, incipient cracks or degradation is not acceptable.

Before running real-world field tests in dedicated proving grounds, the validation of a vehicle’s structural integrity is conducted as a full simulation on a PC and as tests in automated test facilities in durability labs. Here, road load data is reproduced by actuators. Read more about lab testing

 


The Perfect Setup for Structural Integrity

HBK Darmstadt is the worldwide centre of excellence for measurement and data analysis of structural integrity.

Get the complete toolbox – from lifetime fatigue analysis based on FEM models to mobile in-field and lab-based data acquisition solutions including powerful EDGE software, and powerful server-based data analytics. This, of course, with the goal of the whole team providing rapid test and analysis and providing an efficient outcome towards management sign off.

Benefits Using HBK for Structural Integrity

Accelerate testing in all areas – simulation, field and lab. Focus on your data, simplify your development and de-risk your testing.

The HBK structural integrity toolbox allows you to orchestrate and act on your simulation and testing data from your individual virtual and physical test specimen.

  • Dramatically reduce time and resources, working with HBK experts, the seamless tool chain and all necessary services
  • CAE-based fatigue analysis and simulation with nCode DesignLife
  • Complete measurement chain of strain gauges, data acquisition systems and software, with all components working together perfectly
  • Broad portfolio of electrical strain gauges with short delivery times, including pre-wired gauges for immediate use
  • Data acquisition system input schematics with highest immunity against electromagnetic interference and thermal drift due to carrier frequency technology, distributable amplifier modules and auto-calibration on all channels
  • Compensation of cable effects with 4-, 5-, and 6-wire circuit-based patented amplifier technology
  • Same data acquisition system for Road Load Data Acquisition (RLDA) and lab testing
  • DAQ system perfectly integrated into MTS-329 road simulator rigs with FlexTest/RPC Pro and into MAST and all component test stands with INSTRON LabSite
  • Complete software solution for the application, ready-to-start without programming
  • Powerful interactive post-acquisition analysis and visualization using nCodeGlyphWorks
  • Server-based streamed data processing using nCodeDS
  • Overall data management and collaboration using Aqira
  • Material testing and evaluation as a service with HBK testing equipment

HBK System Openness

Integrate the best fit hardware combinations from different vendors in your overall testing solution with technologies such as EtherCAT, PROFINET, ASAM XCP-on-Ethernet or a simple API.

Examples:



Questions? Get in touch! We’ll be happy to help you.

QuantumX / SomatXR DAQ: Parallel Data Acquisition and Control

Supports standard TCP/IP Ethernet and Industrial Ethernet standards such as EtherCAT® to:

  • Reduce cable wiring, number of inputs on the controller side and overall cost
  • Reduce setup time and cost
  • Reduce complexity and possible errors
  • Increase availability and time for testing, and shorten development times
  • Improve data quality and overall reliability
  • Allow single time stamp and different clock cycles (distributed clock, 3 sync managers)

Learn more: QuantumX ­     Learn more: SomatXR ­

QuantumX and ruggedized SomatXR DAQ systems have the same analog input path and can be combined in a flexible way – both data acquisition systems offer the same in-field and on-bench functionality and integration opportunity.

catman Software and Analytics

catman is comprehensive and adaptable non-programmable software, conceived for data acquisition, online calculations and analysis by monitoring the entire testing process. It features extensive reporting functions with a graphical presentation of the results.

All acquired measurement data sets run into data analytics, by rainflow cycle counting and the Monte-Carlo methods. The software offers either the creation of a fatigue curve (Woehler) or a variable amplitude fatigue curve (Gaßner).

The efficient and process-oriented workflow reduces cost and shortens testing times.

Learn more: catman software­


Structural Durability Testing: From Lab to Road

A Structural Durability Lab Testing Assessment is one of the last stages before a vehicle prototype can be released onto the market. To create structural test programs covering true market requirements, hydraulic, pneumatic and electric actuators, vibration tables and climatic chambers are used.

An operation profile defines the conditions to be monitored but also the target damages of the accelerated testing. In the lab, mainly strain and force-based measurements are used to characterize loads under replayed real-world operating conditions and calculate resulting accumulated fatigue damage.

To authentically imitate the road in numerous types of dynamic and static tests, different loads applied to the system under test are reproduced:

  • Multi-axis, full-scale 4-poster road simulation, covering six degrees of freedom
  • Vehicle stress and strain analysis
  • Bi-axial, axial-torsional, multi-axis load machines
  • High-cycle and low-cycle fatigue
  • Thermo-mechanical fatigue
  • Fracture mechanics
  • Crack propagation and growth studies
  • Fracture toughness, high strain rate, quasi-static, stress-relaxation
  • Steering system validation and static strength, torsion, bending
  • Ultimate strength testing

In Road Load Data Acquisition (RLDA), the vehicle is equipped with additional sensors: Strain gauges (SG), acceleration sensors, string potentiometers, special measuring wheels on one or two axes for force and torque measurement, GNSS/GPS/IMU sensors for position and kinematics, as well as video cameras for recording the driving situation.