1. Higher Speeds, Greater Challenges in Validation

As train speeds increase, the interaction between vehicles and tracks becomes more complex, making issues such as structural vibration, dynamic loads, contact and impact, and operational stability increasingly critical. For high-end equipment in fields such as automotive, aerospace, robotics, and construction machinery, the continued pursuit of higher speeds, lighter structures, and greater intelligence is exposing the limitations of traditional R&D approaches based on experience-driven design, multiple prototype iterations, and physical testing. These methods often involve high costs, long development cycles, and limited efficiency when adjustments are required.

Fig. 1: DAP Software Interface

DAP (Dynamics Analysis Platform) is a multibody dynamics simulation software designed for the development of high-end equipment. During product concept evaluation and R&D design, it provides users with capabilities for kinematic, dynamic, and rigid-flexible coupling simulation and analysis. At its core is a multibody system dynamics solver, integrated with functions including parametric modeling, kinematic and dynamic analysis, modal analysis, sensitivity analysis, parameter optimization, 3D contact calculation, electromechanical-hydraulic co-simulation, contact and wear analysis, and visualization and post-processing. These capabilities enable R&D teams to rapidly build “functional virtual prototypes,” identify potential risks at an early stage, and compare different design solutions.

2. Building a “Digital Test Track” Before Testing on the Real Train

Simulation of complex equipment is not simply about recreating the product’s physical appearance. Engineers must translate parameters such as mass, materials, connections, load conditions, and modes of motion into computable digital models. These models then undergo parameter configuration, simulation, result analysis, and design optimization to identify potential problems that may arise during real-world operation.

DAP adopts a modular and scalable software architecture. At the foundation layer, it integrates a multibody dynamics solver, rigid-flexible coupling modeling, nonlinear contact and collision analysis, integration algorithms, data interfaces, and multidisciplinary co-simulation interfaces. The middle layer provides basic model libraries, industry-specific application modules, parametric templates, and intelligent optimization tools. The application layer offers capabilities including rapid visual modeling, task management, result post-processing, script execution, animation, and report generation.

Fig. 2: DAP Software Technology Framework

Through its graphical interface, users can perform model construction, load condition setup, parameter sweeps, result comparison, and optimization analysis. The platform connects the previously separate processes of modeling, simulation, and optimization, reducing the data loss associated with repeated transfers between different software tools and making professional simulation increasingly reusable, scalable, and process-oriented.

3. Tackling Complex Operating Conditions: Simulation Must Be Both Accurate and Fast

The key challenges in simulating high-end equipment often involve contact, collision, friction, clearances, and material nonlinearities. As models more closely replicate real operating conditions, computational demands typically increase, placing greater requirements on solver speed, stability, and accuracy.

To address these challenges, DAP combines proprietary algorithms, a modular architecture, intelligent optimization, and engineering-oriented interaction. The platform employs an efficient rigid-flexible coupling algorithm for multibody systems and optimizes sparse matrix solution strategies to improve the iterative efficiency of conventional algorithms. It also integrates adaptive genetic algorithms with dynamic simulation iterations to enable intelligent optimization of simulation parameters, reducing the need for repeated manual adjustments.

Fig. 3: Dynamic Testing and Validation Scenario

In contact and collision analysis, the platform optimizes computational models for nonlinear factors such as friction and clearances, improving simulation reliability under complex conditions involving high-impact loads and high-speed motion. Based on measurements from typical applications, the platform can achieve simulation accuracy within 1%, improve data processing efficiency by more than 65%, and help shorten R&D cycles by 30%–35%.

4. Virtual Simulation Does Not Replace Physical Testing—It Makes Testing More Precise

If design problems are only discovered after a prototype has been manufactured, companies may need to revise the design, replace components, or even build another prototype. For complex and costly equipment, each round of rework brings additional time and financial costs.

Following the technical workflow of “parametric modeling → dynamic simulation → result post-processing → experimental validation → parameter optimization,” DAP shifts part of the engineering validation process from the physical prototype stage to the digital prototype stage. Through virtual simulation, engineers can identify potential issues involving vibration, impact, contact, dynamic stress, fatigue, and operational stability in complex mechanical systems at an early stage, providing quantitative support for concept evaluation, design optimization, and test preparation.

Figure 4: Application Scenario for High-End Transportation Equipment

5. From CR400 to CR450: Bringing Simulation into the R&D Process

DAP has been applied in the R&D and design of next-generation high-speed train equipment, including CR400 and CR450, as well as other power-concentrated railway vehicles. It supports system dynamics modeling, operational stability analysis, dynamic performance evaluation, key parameter optimization, and test plan development, providing simulation support for the design and validation of high-end transportation equipment.

As high-speed rail moves toward higher operating speeds, vehicle systems require more rigorous analysis and validation across complex railway lines, different speeds, and diverse operating conditions. Dynamic simulation enables engineers to compare key parameters before physical testing, identify potential risks at an early stage, and provide a basis for subsequent structural optimization and test planning.

Fig. 5: Overseas Engineering Testing and Simulation Applications

Overseas, the company’s technical team has conducted dynamic performance testing and evaluation for engineering projects in Russia, India, Brazil, and other countries. DAP has been used to support multibody dynamics simulation and test plan development, providing technical support for performance validation and adaptability analysis under real-world operating conditions. The platform has also collaborated with institutions including the University of Huddersfield in the UK on rigid-flexible multibody dynamics simulation and applications for complex transportation systems, helping bring domestically developed industrial simulation software into more international engineering and research settings.

5. Beyond Cost Reduction and Efficiency Gains, Greater Importance Lies in Technological Independence

Based on typical applications, DAP can replace some overseas commercial software licenses and technical services, saving users millions of yuan in licensing fees each year. In engineering R&D, it can help reduce R&D costs by 28%–30%, improve data processing efficiency by more than 65%, and shorten development cycles by 30%–35%, while also reducing subsequent operation and maintenance costs.

These benefits extend beyond cost and time savings. By moving simulation analysis earlier into the concept evaluation and design stages, companies can obtain quantitative evidence earlier, improve R&D decision-making efficiency, and enhance product reliability. Continued adoption of domestically developed dynamics simulation platforms can also reduce the costs of purchasing, renewing, and customizing high-end industrial software while strengthening independent control over critical R&D toolchains.

Conclusion

As CR450 advances toward commercial operation at speeds of 400 km/h, and high-end equipment in aerospace, automotive, robotics, and other fields continues to evolve, competition in complex equipment is no longer limited to materials, structures, and manufacturing capabilities, but increasingly extends to modeling, computation, simulation, and validation capabilities.

Before physical equipment enters manufacturing and operation, identifying risks, comparing design options, and optimizing parameters in the digital space is becoming an important R&D approach in advanced manufacturing. As a domestically developed and independently controlled dynamics simulation platform, DAP is positioned to provide more efficient and reliable technical support for the development of complex equipment.

Beijing XJTU Zhizhong Software Technology Co., Ltd.

Beijing XJTU Zhizhong Software Technology Co., Ltd. was established on March 3, 2017. The company specializes in the R&D and innovation of multibody dynamics simulation software, with 100% independent intellectual property rights and core technologies. It provides industrial design and development professionals with software tools and services for multibody system dynamics simulation, analysis, optimization, and related applications.

The company has assembled a highly skilled technical team, with core members drawn from leading institutions including the National Key Laboratory of Rail Transit Vehicle Systems, the University of Science and Technology of China, and Beihang University. Led by Academician SHEN Zhiyun, the team’s engineers hold master’s degrees or higher, while its senior experts have more than 30 years of experience in finite element analysis, multibody system dynamics, multidisciplinary co-simulation, and experimental testing.

Building on the technical expertise of the National Key Laboratory of Rail Transit Vehicle Systems, the software development team has long focused on the development and advancement of core industrial software with independent intellectual property rights. Leveraging its technical capabilities and industry experience, XJTU Zhizhong aims to overcome reliance on foreign technologies, advance independent innovation in China’s industrial software sector, and provide efficient and reliable simulation solutions to support the intelligent upgrading of Chinese manufacturing.