How to Ensure the Performance of Heavy Equipment?
Known also as engineering equipment or heavy machines, heavy equipment represents a large category of heavy-duty vehicles and big industrial machinery. Having as common attributes strength, oversized dimensions, working performance and long life cycle, heavy equipment is an essential component of the workflow process in many powerful demanding industries like, mining, oil and gas, energy, forestry, construction, civil engineering, military engineering, transportation and many others.
Including high powerful machines like wheel loaders, bulldozers, graders, cranes, oversized trucks, heavy forklift or wood gathers, the heavy equipment industry has been experiencing a near 6% worldwide growth rate during the last decade . This development is fuelled by the permanent needs of humanity of natural resources, geographical spaces exploration, industrial development, transportation infrastructure and new building and architectural big investments.
Heavy equipment overview
Industries using heavy equipment are diverse and encompass many aspects of everyday life, from road construction to forestry, farming, and manufacturing to oil and mineral mining to public works and military applications.
Starting from the main applicability criteria, we can generally classify a wide range of heavy equipment categories :
- Mining equipment – horizontal drills, mining tractor, mining trucks, mining wagons
- Track-type – Tractors, bulldozers, snow cats, track skidders, agricultural tractors, and military engineering vehicles, graders, skid steer loaders;
- Excavator – Dragline excavator, wheel excavator, front shovel, trencher machine, yarders, pipe layer;
- Articulated – articulated hauler, articulated truck
- Backhoe – Backhoe loader,Backhoe
- Compactor – wheel dozers soil compactors, soil stabilizer
- Highway, Railroad – dump truck, highway dumps, transfer train, transit-mixer, street sweeper,
- Hydromatic Tools – ballast tamper, attachments, drilling machine, pile driver, rotary tiller
- Loader – loader, skip loader, wheel loader, track loader
- Material Handler – aerial work & transportation platform, cherry picker, crane, forklift, trailer mount, reach stacker, telescopic handles
- Paving – asphalt paver, cold planer, cure rig, paver, pneumatic tire compactor, road roller, slip form paver, vibratory compactor
- Scraper – Fresno scraper, scraper, wheel tractor-scraper
- Timber – Feller buncher, harvester, skidder, track harvester, wheel forwarder, wheel skidder
- Underground – road header, tunnel boring machine, underground mining equipment
Heavy Equipment — Manufacturing Challenges
Attaining high performance of heavy equipment requires a better manufacturing process, innovative design and best quality raw material. Increased competitiveness is stimulating heavy engineering processes to adopt frontier technologies and large scale manufacturing automation.
Starting from the classic manufacturing process based on the common workflows, from design and testing to production and field installation, the heavy equipment industry is faced with specific difficulties related to oversized dimensions, high quality of materials, working performance and long-time exploitation. Let’s see how big and how heavy are few of such equipment types and how difficult is the machine manufacturing process.
The Versatile Model 1080 „Big Roy” is one of the biggest tractors in the world . Designed and built in 1977 by Versatile Manufacturing Ltd. from Winnipeg-Manitoba, Canada, this 30 tones massive tractor is 30 ft (9.1m) long, 22 ft (6.7m) wide, 11 ft (3.35m) high and powered by a 600 horsepower Cummins KTA-1150 diesel engine. The four axles mounted a total of eight 30.5 X 32 tires. A modern, spacious cab is located ahead of the engine compartment with a 550 (2082l) gallon fuel tank located ahead. Because vision to the rear of the tractor from the cab is very limited as the engine compartment was quite tall, a closed circuit TV system was installed with a dustproof 120 degree camera pointing down at the drawbar and a 9 inch TV monitor installed in the dash.
Designed in 2004 by the German manufacturer Liebherr Mining Equipment Co., Liebherr T 282B is considered the largest earth-hauling truck in the world . Having as dimensions 14.5 m (48 ft)in length, 8.7 m (29 ft) in width, and 7.4m (24 ft) in height, the super-truck is powered by two diesel engines 3,500-horsepower coupled to a Siemens-Liebherr AC electric drive system. Fully loaded, the T 282B can achieve a top speed of 40 mph (64 km/h). Due to its exceptional size and weight, the T 282B cannot be driven on public roads. The T 282B is shipped in component form to the customer site before undergoing final assembly.
Simulation in Increasing the Performance of Heavy Equipment
The previous are only two examples of engineering performances in the heavy equipment industry. Any manufacturing process for most powerful equipment should assimilate modern engineering and design solutions able to reduce time, risk errors, and money. Integrated CAD/ CAE solutions allow real-time corrections, dramatic cost reduction associated to physical testing of prototypes, and continuous improvement of product quality and performances.
Whether it’s used to virtually test heavy machines or their parts, the SimScale simulation platform has all the functionalities to obtain the required data for making changes and optimizations early in the design process. Without any physical prototypes, the design engineer is able to improve and ensure the performance of heavy equipment early in the design process. Let’s see a few heavy equipment simulation examples available in SimScale’s Public Projects.
Structural Analysis of Heavy Machines’ Components
Described also in a previous SimScale blog article, the Wheel Loader Arm project shows how a static linear structural analysis of a wheel loader arm is performed. The simulation results show the relative movement between the components and at the same time allow an assessment of the stress performance. With the results control two area calculations were made to check which forces the hydraulic cylinders generate to lift the applied load. The figure below shows the von Mises stress response of the analysis.
This simulation performed with SimScale is a static structural analysis of a gripper arm. The main results of the simulation are showing the von Mises stress performance and the displacement of the model. Most interesting is the filter warp by vector analysis applied to illustrate the movement of the geometry. As is show in the image, the displacement of the gripper arm is not symmetric. This is caused by the asymmetric positioning of the hydraulic cylinder and the additional connection truss between the two gripper arms. The design engineer can now alter the geometry to ensure a more symmetric behavior of the arm under load and therefore improve the stress performance.
Dynamic Analysis of Gears
Gears are machine elements that transmit motion by means of successively engaging teeth. According to the relative position of the axes of revolution, gears may be parallel, intersecting, and neither parallel nor intersecting .
In the SimScale gears dynamic structural analysis project a couple of gears in contact is demonstrated. For simulation purposes the smaller gear was completely fixed in its inner face. All degrees of freedom of the other gear were fixed, too, except the rotation around the x-axis. On the inner face of the bigger gear, a moment was induced by a remote force with a torque of 20 Nm. Only a small portion of the faces, which will be in contact, was subject to a frictionless augmented Lagrange contact boundary condition. After the simulation design, a dynamic structural analysis was carried out. The results allow the engineer to check the stress performance of the gears in contact early in the design process, so he can alter the design, take another material or check what parameters to use for a case hardening. The two pictures below visualize the von Mises stress response as well as the displacement field.
Harmonic Analysis of Rotating Components
Impellers are common rotating components of a centrifugal pumps, usually made of iron, steel, bronze, brass, aluminium or plastic, which transfers energy from the motor that drives the pump to the fluid being pumped by accelerating the fluid outwards from the centre of rotation .
In this impeller harmonic analysis project, the structural response of an impeller to vibrational loading is analysed. The impeller is supported by two oil bearings. The right bearing is fixed while at the left bearing the harmonic excitation is applied. The stress and deformation fields due to this excitation are analysed via the harmonic analysis type on SimScale. First, a large frequency bandwidth from 10 to 1670Hz is analysed in order to identify critical frequencies. The resulting magnitude response visualized in the left figure shows that 520 Hz is the most critical frequency. A second harmonic analysis is therefore carried out for this specific frequency and additionally the resulting displacement and stress field is printed out for a post-processing review. These fields show that both the deformation and the stress field do have critical regions for the material type used.
Airflow Analysis of Heavy Machines Components
In this airflow simulation of a radial impeller, the airflow domain around the impeller has been uploaded in STEP format to the SimScale platform including a specific solid body for the rotating domain around the impeller. The simulation was set up using the analysis type for steady-state, turbulent flow utilizing a k-Omega-SST turbulence model. Additionally the rotation of the impeller was simulated using a rotating reference zone around the impeller. The simulation results enable the early visualization of the pressure and velocity field as well as numerical values regarding pressure increase and volume flux.
All the projects presented in this article can be imported into your own workspace from SimScale’s Public Projects and used as templates.
If you haven’t signed up for SimScale yet, you can create your free account here and see for yourself how 3D engineering simulation can help you increase the performance of heavy equipment.
 Heavy_equipment, Wikipedia
 Liebherr_T_282B, Wikipedia
 Zhang Y., Finger S., Behrens S. – „Introduction to Mechanisms”, Carnegie Mellon University
 Impeller definition, Wikipedia