With the demand for unquestioned durability, backhoe engineers need to determine load capabilities early in the development cycle. And they need to look at a variety of usage scenarios: high loads for hauling heavy equipment and variable loads for different types of earth-moving tasks, such as soft ground compared to rocks and gravel. As a durability engineer, they need to understand complex load distribution as well as guarantee that the machine can handle the heaviest lifting time after time without mechanical failure.
Designing it right has always been the motto of Turkish construction equipment manufacturer Hidromek. Founded in 1978, this family-run backhoe loader and hydraulic excavator manufacturer employs about 1000 people at its facilities in Ankara. Today, the company makes machines ranging from 14 to 37 ton (13 to 34 t), including the Maestro backhoe series created by the company’s in-house design studio.
With production reaching just over 10,000 backhoe loaders and excavators annually, the company is seeing a rise in worldwide popularity, selling in over 50 countries. The challenge for the owners, Hasan Basri Bozkurt and his two sons Ahmet and Mustafa, is to maintain the momentum, making sure that Hidromek products stand up to the task at hand in regard to aesthetics, ergonomics, and performance. And one way to do this is by focusing on durability engineering.
From an engineering perspective, much can be done upfront in the development process to explore the workability of the final design, but the main difficulty with regard to durability issues resides in gaining a realistic understanding of the actual loads that the equipment and its components can handle. Normally, steps in the development process to check design durability include obtaining on-site measurements, quickly and accurately processing the obtained data, and feeding the data back into the respective test rig or simulation model to confirm design feasibility.
Rather than offering just a basic data acquisition tool, LMS provided Hidromek with an actual durability solution that covered the complete development process. “It was better for our design vision and helps us to understand the real loads capability. In the end, this translates to improved equipment performance, better ergonomics, and longer life cycles,” said Ferhan Ficici, R&D Director at Hidromek. Beyond pure data acquisition, the LMS tool set supports Hidromek’s efforts to better understand realistic loads for improved equipment performance and longer life cycles. Multiple possibilities for dynamic fatigue assessment, block-cycle test definition, accelerated testing, or fatigue life prediction are built in the LMS complete solution portfolio.
With the LMS system in-house, Hidromek’s team has taken durability engineering to the next level with across-the-board improvements not only in the overall process but also in the quality of the measurements, more thorough data analysis, and faster processing times.
During a normal durability test cycle, the first task at hand for the engineering team is to acquire real-life operational data. For this, Hidromek engineers can access a total of 112 channels by combining the power and capacity of their two separate LMS SCADAS Durability Recorder data acquisition systems. While the LMS SCADAS Durability Recorder 09 measures strains, stresses, and other loads in the cabin, the other LMS SCADAS Durability Recorder 07, mounted under the machine’s frame, acquires the real workaday load data. The two systems remain synchronized thanks to GPS time data, which eliminates the hassle of additional cables between units. With simultaneous PC-free data acquisition, the Hidromek engineers can acquire all the durability data they need in a single test run. They can also validate the data on site using a PDA.
Ficici explained: “The LMS solutions are very user-friendly. Especially, the LMS Test.Xpress data acquisition software is extremely easy to use. Tests are quickly set up; the overall test preparation time decreases. Just one click is enough to balance all channels. Before, test preparation and execution used to be a lengthy process. I felt that the time we spent in measuring data was out of proportion for the results we got. Today, overall measurements time is reduced by half.”
Once the team obtained the data and validated it, LMS TecWare was used to analyze and compare the obtained measurements with previous ones.
“Thanks to the data management and durability-specific characteristics of LMS TecWare, it is easy to create an overview report that can be used by other departments for simulation or studies on hydraulic test rigs. We also appreciated the fact that LMS TecWare accelerated the testing phase without having to omit non-damaging events from the measured loads or oversimplifying a test to a uni-axial block cycle test. Today, we base our design criteria of structural parts on some assumptions and then perform strength analyses and calculations. The new process, implementing the LMS SCADAS Recorder and LMS TecWare, allows us to verify if these assumptions are true or not. Hence, it is possible to validate the structural parts of our products. This results in more reliable products,” Ficici said.
The team employs the same LMS SCADAS acquisition system when performing Human Body Vibration measurements or verifying compliance with ISO standards for sound power. For development studies, octave-band analysis and FFT analysis are performed. Similar spectrum analyses in frequency domain are performed for vibration measurements. FFT, PSD graphs are generated by using time-series data. Also, weighted RMS values are calculated for different maneuvers of earth-moving machines. Using the same hardware and software platform for different types of applications saves both costs and time but not at the expense of job-specific tasks, which are fully supported in the platform.
Joelle Beuzit, Product Marketing Manager at LMS International, wrote this article for SAE Off-Highway Engineering.