Accelerating crane development via Tadano’s breakthrough in structural stress evaluation

Delivering optimal construction and infrastructure solutions

Tadano Ltd. is a construction machinery manufacturer with significant market share in cranes and aerial work platforms. Leveraging a broad product lineup and proven engineering expertise, Tadano delivers optimal solutions for construction and infrastructure projects worldwide. Tadano emphasizes safety, quality and efficiency in its manufacturing processes and consistently works to improve the strength, durability and safety of its products.

Recently, Tadano incorporated Siemens Digital Industries Software simulation technologies to streamline its design and development processes and further enhance product quality.

Simcenter Simsolid can represent the entire crane, making quantitative analysis possible.

Their challenge

Tadano runs simulations to thoroughly evaluate and analyze product performance. However, before reaching that critical stage, they faced a significant bottleneck in the workflow: the meshing process. This single step alone demanded a significant investment of both time and resources, slowing down the overall development cycle.

Tadano recognized the potential of using Simcenter™ Simsolid™ software to eliminate the meshing process entirely, transforming simulation from a time-intensive task into a rapid and streamlined, analysis-driven workflow. This promise of efficiency and precision was a key factor in their decision to adopt Simcenter Simsolid, which is part of the Siemens Xcelerator business platform of software, hardware and services.

Additionally, Tadano’s cranes can extend over 100 meters in length, but the critical stress concentration areas they need to evaluate are often localized within a few millimeters. This created a significant gap between the overall product scale and the mesh element size needed for accurate stress analysis.

To overcome the gap between large-scale structures and highly localized stress areas, Tadano engineers had to rely on several simplification techniques within the conventional simulation process:

• Extracting and modeling only portions of the structure
• Applying customized boundary conditions
• Using shell elements instead of the solid elements
• Removing small but complex features like holes and components

Although these methods helped reduce model size and computational load, they inevitably introduced discrepancies from the physical product – a compromise the team had to accept. Over time, Tadano began to question whether conventional finite element methods (FEM) were truly suitable for analyzing large, highly complex structures.

A simple model of a cantilever beam was created to verify the effect of local stress due to model division.

Our solution

The team turned to Simcenter Simsolid to simulate the entire product geometry without the need for these simplification techniques. However, in practice, a new challenge emerged: although full product geometry could now be modeled accurately, the stress distribution in critical, localized areas sometimes appeared unrealistic.

The engineering team sought to find a method to accurately represent stress concentrations in these critical areas using Simcenter Simsolid.

The solution came with the development of a targeted screening and refinement strategy. Tadano engineers identified areas of high stress and isolated them into smaller, localized subparts. This approach prompted Simcenter Simsolid to automatically generate a finer response mesh in those regions. The “response mesh” is the visualization mesh that Simcenter Simsolid automatically generates to display contour plot results.

The result was a significant improvement in accuracy. Stress distributions in critical areas became noticeably clearer and more precise, enabling confident design decisions without the compromises of traditional methods. Leveraging Simcenter Simsolid bridged this gap, enabling accurate stress evaluation without the time-consuming complexities of conventional meshing.

Stress result visualization improves with increasing refinement close to the stress concentration.

Results

By subdividing critical areas into smaller components, Tadano engineers were able to prompt Simcenter Simsolid to automatically generate a finer response mesh in regions with stress concentrations, significantly enhancing the resolution and accuracy of the results.

“With Simcenter Simsolid, we can now perform simulations that were previously impossible, such as stress evaluation without simplification, or natural frequency estimation on full assembly models,” says Toshiyuki Miyajima, assistant manager of the advanced technology development department. “We are also satisfied with the solution’s accuracy. The stress values calculated internally by Simcenter Simsolid are highly reliable.”

Left: Initial result visualization. Middle: Result visualization after split strategy refinement. Right: FEM reference result visualization.

In Simcenter Simsolid, response mesh generation is governed by a range of computational factors beyond direct user specification, ensuring that refinement adapts dynamically to the unique characteristics of each case rather than following a uniform scheme.

Despite this, the resulting stress distribution results in high-concentration areas closely aligned with those obtained through traditional FEM methods, validating the approach and increasing confidence in the simulation results. Using Simcenter Simsolid to assess complete crane structures allowed the Tadano team to make the simulation process ten times faster.

Efficiency gain with Simcenter Simsolid as alternative to FEM.