Identify the locations that warrant attention in a joint group.
Organize long-term observation around the bolt ring, periodic retesting, link status, and maintenance records
Track changes in the joint
to support maintenance decisions.
Ultrasonic bolt force monitoring and maintenance
From one inspection to ongoing monitoring.
Keep location, measurement and maintenance in one service history.
Critical bolted joints · Wind turbine blade root example
Root thread connection · 48 schematic measurement points.Drag to Rotate · Click to Measure Point
observing B-17Requires Attention
338.0kNBolt force at the reference condition 84.5% of baseline
Looking down along the variationSame connection, continuous observationDay 90
Initial preload 400 kNperiodic retestingcontinuous monitoring
The scale shows bolt force as a percentage of baseline. The joint and monitoring history are illustrative.
Relate every observation
to thesame joint.
Periodic retests provide distinct observations. Online monitoring records continuous changes.
Compare the records at the same location, for the same bolt and under comparable conditions.
periodic retestingA single test with conditions and results
shared history
online monitoringRead continuously changing conditions with operating conditions
Thread root connection APosition is retained, individual is independently traceable
example rangeattention / alarmMeasurement Pending Reviewunknown/interrupted
Spatial position and historical records jointly locate changes.
fastened joint A / bolt location
Requires AttentionB-17S-17-A
Bolt force at the reference condition338.0 kN
relative to current baseline84.5 %
Measurement Comparabilitycomparable
Online reference operating conditionperiodic retestingservice baselineexample focus line
up to
Only the same object can have comparable changes.
Select two records to compare measurement conditions and bolt force.
Day 90Day 120
Synthetic Scenario Data · Example Baseline and Rules · Do Not Make On-Site Safety Judgments
See the reading
andthe evidence behind it.
From echo to time of flight, and from calibration to bolt force. Interpret changes using the measurement location, reference, temperature and events in the measurement chain.
B-17 / Echo contrastRelative service baseline echo time shift
reference echocurrent echoTemperature Corrected
Original time of flight change—
Temperature Influence Item—
corrected ultrasonic time of flight change—
Synthetic waveforms and simplified conversions illustrate the measurement chain. The research data is shown separately below.
View the conversion relationship and comparison conditions of the demonstration
The demo uses a linear sensitivity of 0.42 kN/ns and a temperature coefficient of 0.58 ns/°C. The observed time-of-flight change includes contributions from bolt force, temperature, and possible measurement-chain drift. Subtracting the temperature term leaves any measurement-chain drift unresolved. These coefficients are demo inputs independent of the study data below and are unsuitable for field setup.
Zero load measurement reference is used for axial force conversion, service baseline is used for historical comparison. Replacing bolts requires new individual records; if there is a missing baseline, data interruption, or reference to be verified, direct decay conclusions are not output.
Turn an observation
intoa recorded action.
Discovery, verification, maintenance, re-verification. Each step returns to the same bolt position, retaining the original basis and leaving subsequent changes.
current object
to be scheduledB-17No retest has been scheduled
- 1Location changes and basis
Verify the current focus in terms of spatial position, history, and measurement conditions.
- 2Schedule and record retesting
Clearly check the object and measurement premise, retain new re-measurement results.
- 3Verification Again After Maintenance
Record processing events, compare subsequent valid results, and retain the previous history.
Operable preset maintenance scenarios; tasks and records are only demonstrated within the current browser page
TD SentinelInspection summary / exampleKeep a summary
of measurements and maintenance evidence.
- Connection Location
- Root connection A / B-17
- observation time
- Day 90
- measurement basis
- identity, reference, and baseline
- maintenance history
- waiting for creation
historical curveevent recordcomparison conditionfollow-up matters
Exported content follows the current measurement point, time, rules, and task status, with a scenario data identifier included.
Use the evidence
to decide what comes next.
AI monitoring assistant works by starting with understanding the current joint. Compare records, locate references, organize re-measurement tasks, keeping analysis and action aligned.
Explanations have sources, recommendations have context
SSentinel Monitoring Assistantcurrent B-17
Around the currently selected bolt, view measurement, history, and maintenance basis.
The product starts
withtraceable research.
Current work focuses on ultrasonic calibration, hysteresis and measurement stability. These studies help convert measurement prerequisites into clear records in the software.
ultrasonic time difference and external loadHistorical calibration data · 50 sets of organized points
data organization pointLinear reference fit on this page
Fitting only explains the relationship of this set of data, does not represent device accuracy or long-term monitoring accuracy
Use the calibration relationship
to understand the measurement assumptions.
A single measurement must be saved together with the bolt individual, reference state, and calibration relationship. The model's applicability and actual measurement conditions should also be considered as results are seen.
Existing research has also analyzed repeated measurements under fixed conditions, link reconnections, and changes in monitoring objects. Long-term serviceability will continue to rely on field data and independent verification.
Data sources and applicable range
Data is organized from historical ultrasonic axial force calibration records, including 50 sets of time of flight differences and external loads, with project and field identities removed.
An echo carries
more information than a single bolt force value.
Place two observations on the same time scale. Retain waveform contours, time of flight readings, and link events, making changes traceable.
Complete view · about 25–59 µs
Move or Tap the Curve to View Time Position
Earlier recorded / CH1 ultrasonic time25134.29ns
Later recorded / CH1 ultrasonic time25136.33ns
Time-of-flight difference between the two screenshots+2.04ns
The change in readings needs to be interpreted together with the connection event and reference state.
Redraw based on historical test screenshots. The curve retains the upper and lower contours of visible trajectories, not the original sampling data; time of flight readings are preserved as in the original image.
View Redraw Basis and Documentation
The source comprises earlier and later records from one brief sensor-detachment test (11.JPG and 21.JPG, TchUS8 V3.1). The horizontal axis follows the time scale of the original screen. The vertical axis shows normalized amplitudes on a common image scale. The traces were extracted from the screenshots for visual waveform comparison. They cannot recover the original sampled sequence. The time-of-flight difference of 2.04 ns was read from the screen. The reconstructed curves do not establish that value, causation, or device accuracy.
TD Sentinel is in the product development stage. This page shows the product direction; the monitoring interface uses synthetic scenarios, and the points and historical echoes are separately marked with sources.
From one blade root
to othercritical joints.
Organize positions by connection objects, comparisons by measurement conditions, and maintenance events by history. This method should be able to expand with scenarios.
Compare one inspection with the next.
Retain measurement point identity, reference conditions, and inspection batch, trace the state changes of the same connection
Bring scattered records into a workflow you can continue.
Organize data integration and maintenance collaboration for inspectors, equipment management, and technical teams
A deeper analysis
starts with more complete inputs.
Load correlation, fatigue damage, and life studies are part of the future product direction. They require real load spectra, materials, connection models, operating conditions, and independent verification to support them.
inputMeasurement · Operating condition · Load
methodResponse · Damage · Verification
targetmore informed maintenance
Joint design, assembly and service.
TD Axiomdesign objectives and verification basisTD Sensetest measurement and data analysisTD Cadenceassembly process and quality record
TD SentinelService observations and maintenance records
TD Atlas Provide knowledge, standards, and method basis. If service changes require further verification,TD Nexus Focusing on Overall Load Path and Connection Group ResponseTD Forge Facing thread profile, thread root and engagement area details; analysis still needs to be supplemented with real operating conditions, materials and boundary conditions.
Cross-product data collaboration belongs to the kit planning direction, specific integration is subject to official release notes.
Keep your joint
underongoing observation.
Start with a specific structure, measurement condition, or maintenance issue
Discuss how Sentinel can enter your workflow.
engineering applicationDiscuss a monitoring scenarioequipment and dataDiscussion on Access and Collaborationresearch and verificationAccumulate engineering evidence collectively
haoyuruilianTJ@163.com