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A new numerical approach is proposed for studying possible vibrations caused by drilling during the assembly of aircraft structures. It is based on modelling of the stress-strain state of assembled structures by solving the corresponding transient contact problem. This approach is intended for fast dynamic analysis of the structure in the drilling area. It includes a time discretization algorithm, a special reduction technique and a reformulation of contact problem in terms of quadratic programming. The high speed of the algorithm allows one to combine the non-stationary calculations with variation analysis in order to check the possible deviations in the shape of assembled parts. The proposed approach is validated by commercial software and it is also applied for analysis of a test problem.

Sealant is applied between joined aircraft parts in the final stage of the assembly, before installation of permanent fasteners. In this paper a novel approach for aircraft assembly simulation is suggested, which allows to resolve the transient interaction between parts and sealant in the course of airframe assembly process. The simulation incorporates such phenomena as compliance of parts, contact interaction between them and fluidity of sealant with presence of free surface. The approach based on fluid-structure interaction techniques consists of two basic steps: at the first one the pressure of sealant is found after corresponding fluid dynamics problem is solved and at the second the displacements of parts and sealant are calculated through the solving of contact problem. Iterations between structural and fluid dynamics solvers are performed to achieve convergence. The developed approach is demonstrated on example of joining of two test aircraft panels.

The paper presents the numerical approach to simulation and optimization of A350 S19 splice assembly process. The main goal is to reduce the number of installed temporary fasteners while preventing the gap between parts from opening during drilling stage. The numerical approach includes computation of residual gaps between parts, optimization of fastener pattern and validation of obtained solution on input data generated on the base of available measurements. The problem is solved with ASRP (Assembly Simulation of Riveting Process) software. The described methodology is applied to the optimization of the robotized assembly process for A350 S19 section.

ASRP (Assembly Simulation of Riveting Process) software is a special tool for assembly process modelling for large scale airframe parts. On the base of variation simulation, ASRP provides a convenient way to analyze, verify and optimize the arrangement of temporary fasteners. During the assembly of airframe certain criteria on residual gap between parts must be fulfilled. The numerical approach implemented in ASRP allows to evaluate the quality of contact on every stage of assembly process and solve verification and optimization problems for temporary fastener patterns. The paper is devoted to description of several specialized approaches that combine statistical analysis of measured data and numerical simulation using high-performance computing for optimization of fastener patterns, calculation of forces in fasteners needed to close initial gaps, and identification of hazardous areas in junction regions via ASRP software.

The paper is devoted to the simulation of A320 wing assembly on the base of numerical experiments carried out with the help of ASRP software. The main goal is to find fasteners’ configuration with minimal number of fastening elements that provides closing of admissible initial gaps. However, for considered junction type initial gap field is not known a priori though it should be provided as input data for computations. In order to resolve this problem the methodology of random initial gap generation based on available results of gap measurements is developed along with algorithms for optimization of fasteners' configuration on generated initial gaps. Presented paper illustrates how this methodology allows optimizing assembly process for A320 wing.

The paper is devoted to description of features and functionalities of special software complex aimed at global simulation of junction process using efficient numerical algorithms. The paper presents the concept of developed software and its structure. Types of problems, which the complex is applicable for, are enumerated.

The paper is devoted to further extension and development of numerical approach aimed at simulation of riveting process during aircraft assembly (see [1,2,3,4]). Previous research has shown that developed methodology provides reliable results if the rigid motion of bodies being assembled is forbidden. However, some small parts in the airframe assemblies are not supported prior to the junction and can freely move as a rigid body. This fact introduces additional difficulties when solving corresponding contact problem. The paper is devoted to description and analysis of two different modeling approaches that allow taking unsupported parts into consideration when simulating airframe assembly process.

The paper is devoted to further development of numerical methods for simulation of riveting process during aircraft assembly (see [3, 4]). Algorithm modifications that increase computation accuracy, speed and complexity are given. These modifications involve the dual problem solving, incorporation of multiple calculation nets and special two stage procedure for calculation of deformations and stresses arising during assembly.

The paper describes the methodology of contact problem solving that is used in specialized software code aimed at simulation of aircraft assembly process. For considered class of problems it is possible to radically reduce the number of unknowns without loss of accuracy. The results of validation of developed code against physical experiments and commercial FEM codes are also given.