Structural Assessment of Cradle Assembly for Heavy Condenser Transport

Nuclear Facility Project

Overview

Murcott Energy Ltd. was tasked with conducting a comprehensive structural assessment of the cradle assembly used for the safe transportation and positioning of large condensers in a nuclear facility project.

The cradle system is a modular structure designed to carry and move heavy equipment, specifically condensers, while incorporating temporary structural components that are essential during the lifting and positioning phases. The analysis ensured that the cradle system, along with the temporary components, could safely support the condensers through all stages of movement and installation.

The Study

This study aimed to verify the structural integrity of the cradle assembly under various load conditions, with the goal of confirming that all components—both permanent and temporary—could withstand the specified operational and transit forces. The integrity of bolted connections, the impact of temporary structural components, and overall load management were key focuses of the assessment.

Primary Objectives

Load Case Definition

Establish and define the load cases as per project specifications to simulate real-world operational conditions.

Finite Element Modelling (FEM)

Develop a detailed FEA model of the cradle assembly based on the provided 3D CAD model, ensuring accuracy and fidelity in representing the structural components.

Linear Elastic Analysis

Conduct linear elastic analyses to simulate the specified load cases, assessing the cradle system’s response to both static and dynamic forces.

Structural Integrity Assessment

Evaluate the overall structural integrity of the cradle assembly and its temporary components, ensuring that all parts could withstand expected loads without failure.

Von-Mises Stress Analysis

Provide detailed Von-Mises stress plots to identify potential areas of high stress, ensuring that all stresses remain within allowable limits.

Displacement and Deformation Analysis

Generate deformation plots to assess how the structure deforms under load and ensure that deflections are within acceptable tolerances.

Bolt Load Verification

Perform manual calculations to verify the integrity of all bolts in the system, ensuring they can handle the maximum loads encountered during the operational and transit phases.

Methodology and Approach

Murcott Energy Ltd. approached the structural assessment by applying Finite Element Analysis (FEA) using FEMAP 2406 NX Nastran software, both industry-leading tools for structural simulations. The cradle assembly was modelled with the following key considerations:

Material Properties

All structural components were modelled using Structural Steel Grade S275, with the allowable stresses calculated according to Eurocode 3. Temporary structural components, essential for supporting the load during movement, were also included in the analysis.

Element Types

The cradle structure was modelled using shell elements for the main framework, while beam and solid elements were used to represent the bolts and temporary structural components. This approach ensured the model’s accuracy and robustness in simulating real-world behaviour.

Boundary Conditions

Boundary conditions and constraints were carefully defined to replicate the actual support and load-bearing conditions during the lifting and sliding operations. These included the fixed supports at ground intersections and specific constraints at the crawl drive connections during the sliding phases.

Temporary Structural Components

The cradle system’s interaction with temporary structural components was a critical part of the analysis. These components were used to support the structure during the movement process and were subject to significant forces. Their inclusion in the model was essential for understanding the complete system behaviour and ensuring the integrity of the entire cradle assembly during transit.

Load Cases and Operational Conditions

The cradle assembly was subjected to a variety of load cases, reflecting different phases of the condenser transport process:

Each load case was modelled according to Eurocode 1 & 3 standards, with specific factors applied for live, dead, and variable loads, ensuring that the analysis adhered to industry best practices and safety standards.

Load Case 1: The cradle system supported the condenser in a stationary position, with all stresses and deflections found to be within acceptable limits.
Load Case 2: The system supported the condenser while moving, incorporating additional buffer forces. The resulting stresses and deflections were also acceptable.

Results and Key Findings

Stress Distribution

Von-Mises stress plots indicated that the cradle assembly, including both the permanent and temporary structural components, remained within the allowable stress limits defined by Eurocode 3. No areas of critical stress or failure were identified.

Deformation Analysis

The deformation analysis confirmed that the cradle system would not experience excessive deflections during operation, ensuring that the condensers would be moved and positioned with high precision and without risk to structural integrity.

Bolt Integrity

Manual calculations were conducted to validate the bolt loads. The analysis verified that all bolts in the cradle assembly could withstand the calculated axial and shear forces, ensuring the safety and reliability of the bolted connections under all operational conditions.

Temporary Component Assessment

The temporary structural components were fully assessed for their ability to support the cradle system during the lifting and movement of the condensers. These components were shown to meet the necessary structural requirements, providing the required support throughout the transition process.

Conclusion

Murcott Energy Ltd.’s structural assessment of the nuclear facility project cradle assembly demonstrated that the system, including both the cradle and temporary structural components, meets all required safety and performance standards. The FEA results confirmed that all stresses, deflections, and bolt loads were within acceptable limits, ensuring that the cradle system would perform as required during the transportation and positioning of the heavy condensers.

This detailed assessment provided the client with confidence that the cradle assembly, in combination with the temporary structural components, would safely support the condensers through all operational phases. The results also served as a valuable reference for future projects involving similar heavy-lifting and transport operations, offering insights into best practices for cradle design and structural assessment.

Murcott Energy Ltd. remains committed to providing high-quality engineering solutions that ensure the success of complex engineering projects where safety, efficiency, and reliability are paramount.

Get

GetIn Touch

If you or your company are in need of any of our engineering solutions and expertise, please get in touch.

FEA Services Case Studies

View All FEA Case Studies

Structural Assessment of Industrial Processing Facility Framework

Murcott Energy Ltd. conducted a detailed structural assessment of a completed framework of an industrial processing facility.

Find Out More

Structural Analysis of Cable Lay Vessel, ROV A-Frame and Winch System.

Murcott Energy was consulted by a Cable Lay Vessel OEM to provide a structural assessment of their A-Frame and Winch system.

Find Out More

Structural Analysis of Military Aircraft Wing Component

Murcott Energy Ltd. conducted a comprehensive structural assessment of a modified mechanical component incorporated into a military aircraft wing for carrying heavy missile launchers.

Find Out More