## 1 Introduction
These advances illustrate how sophisticated computational methods can lead to safer and lighter bus components. Building upon this progress, further studies are exploring how these methods can be applied to improve passive safety technologies in specific bus configurations. The study [6] aims to develop new passive safety technologies for coaches, focusing on driver safety during frontal collisions, using UNECE R29 regulations to guide experimental and numerical simulations, which compare strain, acceleration, and displacement data to determine if current designs meet safety criteria or need improvements. The LSDYNA finite element analysis of the school bus frame structure as per the AIS029 (Automotive Industry Standards used in India) pendulum impact test, which is also used in the R29 regulations, is presented by [PERSON] et al. [7]. The paper [8] aims to compare existing NCAPs with BNVSAP (Bharat New Vehicle Safety Assessment Program) and suggest improvements by analysing the experiences of older NCAPs and real-world accident data in India and other countries. In [9], the stress analysis simulations of the welded and bolted joints method for the chassis structure of an electric low-floor medium bus are investigated. Joint integrity is critical for maintaining structural performance under impact. A robust optimisation scheme considering uncertainties and tolerance design is proposed to optimise the electric bus body frame for frontal crashes [10]. A triple-objective robust optimisation model is created and solved with a double-loop nested algorithm combining NSGA-III (Non-dominated Sorting Genetic Algorithm III) and SQP (Sequential Quadratic Programming) methods. The results demonstrate enhanced crashworthiness and robustness under practical manufacturing conditions. Such multi-objective optimisation approaches pave the way for safer, more reliable electric buses that can meet regulatory and operational demands. The work [11] highlights the balance between minimising weight and ensuring occupant protection in critical collision scenarios. [PERSON] et al. investigated the design optimisation of a lightweight electric bus body frame, orienting the static performance and side-impact safety. [PERSON] et al. [12] have used FEA (Finite Element Analysis) for various crash conditions (front, side, rear) in Ansys Workbench, estimating stresses, deflections, and energy distribution of the bus body structure. The effect of electric battery mass distribution on electric vehicle movement safety is investigated in [13]--this problem remains a very important influence factor of the shock energy distribution. Proper battery placement not only affects vehicle dynamics but also plays a crucial role in crash energy management. Weight optimisation and structural analysis of an electric bus chassis frame are other topics of consideration [14]. Having studied the nature of the impact (acceleration, boundary conditions, plastic deformations, etc.) based on the above publications, it is appropriate to proceed to existing research on the structure and strength of bus bodies in non-impact conditions. Understanding the structural integrity of bus frames under everyday static and dynamic loads complements impact safety research by ensuring overall durability and passenger comfort. [PERSON] et al. [15] conducted a structural strength analysis of a medium bus's floor frame, which supports static loading from the interior and passengers, comparing materials ASTM (American Society for Testing and Materials) A514, AISI (American Iron and Steel Institute) 1020, and Aluminium 2014-T4. The rise in car ownership in China has increased air pollution, making electric vehicles more attractive despite battery endurance challenges. The paper [16] uses FEA to optimise the lightweight design of an electric bus frame using structural steel and aluminium alloy. The redesigned frame reduces weight and enhances performance by considering four driving conditions (full load bending, torsional, emergency braking, and steering).