Adaptive’s Cynde Murphy to Speak at V&V Symposium
V&V Verification and Validation Symposium
Conference May 15-17
Training & Committee Meetings May 13-14
Westgate Resorts, Las Vegas, Nevada
Dynamic Load and Weld Fatigue Calculation for Validation of a Telescoping Boom Chassis presented by:
Adaptive’s Cynde Murphy, Simulation and Services Manager
Bob LeGrande, Engineer Principal III, Terex Corp., AWP Division – Genie Industries
Kyle Roark, Engineer Principal II, Terex Corp, AWP Division – Genie Industries
Analytical simulation is a powerful tool that can allow for understanding the dynamic behavior and fatigue life of any structure. However, one of the most challenging tasks involved with developing a simulation is developing accurate and realistic load cases, which replicate field strains in the structure, so that it may be used for validation. Once a representative finite element model (FEM) of a structure is created, challenges arise when understanding and applying dynamic loads to the FEM so that correlation and validation with physical testing is accurate. One step further in complexity is being able to calculate dynamic stress profiles for the entire structure, and use those results for further investigation, in this case fatigue estimates.
Historically, analysts have had to rely on expensive prototyping and time-consuming full vehicle measurements, even within the iterations of one design concept. Analyze-Build-Test is quickly becoming a thing of the past, as product development companies strive for quick to market designs. Simulation experts at Adaptive Corporation, in conjunction with Terex, were able to circumvent this traditionally laborious process and develop an efficient and accurate validation process. Our team has leveraged the use of ANSA, ABAQUS, Wolf Star Technologies True-Load™ software and Fe-Safe, to develop an FEM, understand the dynamic mechanical loads and develop a duty cycle for the Terex telescoping boom chassis. This body of work can and will be subsequently used for design, simulation, fatigue analysis, validation and engineering development of iterations of the same chassis structure, as well as similar chassis designs.
The general steps of the process are as follows: FEM Creation of Assembly FEM of the chassis structure was created using ANSA pre-processor software. Instrumentation and Data Acquisition To successfully calculate mechanical loads acting on the Terex Telescoping Boom Chassis for the FEM, accurate strain measurements were required. Using the FEM and the Wolf Star Technologies True-Load™ software, optimal strain gages placement was identified and installed on a test chassis. Strain gage time history data for various proving ground events, such as cornering, washboard, curbs and potholes. Load Calculation and Development Using the time history data for the optimal map of strain gages, the FEM and True-Load™ software, equivalent (dynamic) unit loads were calculated. Fatigue Analysis Using dynamic stress results from the FEM, given a duty cycle that included a combination of various proving ground events, fatigue life estimates of the Terex Telescoping Boom Chassis and critical welds were calculated. Calculating the mechanical loads for this project allows Terex the ability to rapidly iterate on designs for this chassis, as well as provide a starting point for other similar chassis designs. This ultimately saves time and money in their product development cycle by reducing the efforts of traditional design-build-test cycle, by means of “virtual validation.”
If you aren’t able to attend the V&V Verification and Validation Symposium tune in to our on demand webinar: “Dynamic Load Calculation and Correlation of an Aluminum Truck Body,” also presented by Cynde Murphy.