Effect of Hull Obliquity on Crew Protection, Mass and Space Occupancy of Light Armoured Vehicle

Apart from strengthening crew protective capability from gunfire, the hull obliquity in a light armoured vehicle (LAV) affects its weight and comfortable occupancy. Thus, it requires a critical design analysis for the obliqued hull. The study aims to present the optimal design analysis of an obliqued hull structure to ensure comfortable occupancy of the crew along with its minimum attainable weight and higher protection capability from the gunfire. Three geometric models (G1, G2, and G3) were investigated for the LAV hull’s optimal design. The analytical approach was used to investigate the hull obliquity’s effect, and the results were validated using experimental data reported by other researchers. Digital human modelling was adopted for validating the space adequacy of the hull. It was observed that the hull’s crew protection capabilities from the horizontal strike of armour piercing rounds/bullets were improved almost by half and double for G2 and G3, respectively, when compared with G1. The analytical results are also in good agreement with globally accepted experimental data at reasonable variations. The highest protection capability and comfortable occupancy for the targeted users can be achieved by G3 without affecting the mobility of LAV.

School combo-desk comfort assessment: A method for weighing postural factors that affect the overall perceived comfort

BACKGROUND: In recent years, a growing interest in ergonomics and comfort perception in secondary schools and universities can be detected, to go beyond the UNI-EN regulations and understanding how practically improve students’ perceived comfort during lessons. OBJECTIVE: This study aimed to analyse the (dis)comfort perceived by students while sitting in a combo-desk during lessons; it proposed a method for understanding and weighing the influence of postural factors on overall (dis)comfort. METHODS: Twenty healthy students performed a random combination of three different tasks in two sessions - listening, reading on a tablet and writing. Subjective perceptions were investigated through questionnaires, in which the expected and the overall comfort were evaluated; postural angles were gathered by processing photos through Kinovea® software and were used for the virtual-postural analysis, using a DHM (Digital Human Modelling) software; statistical analysis was used to investigate the influence of subjective comfort of each body part on the overall perceived comfort. RESULTS: The statistical correlations were used to perform an optimization problem in order to create a general law to formulate the overall comfort function, for each task, as a weighted sum of the comfort perceived in each body part. The test procedure, additionally, evaluated the influence on comfort over time. The results showed how the upper back and the task-related upper limb are the most influencing factors in the overall comfort perception. CONCLUSIONS: The paper revealed a precise and straightforward analysis method that can be easily repeated for other design applications. Obtained results can suggest to designers easy solution to re-design the combo-desk.

Using Virtual Reality and Smart Textiles to Assess the Design of Workstations

This paper presents a solution that integrates a smart textiles system with virtual reality to assess the design of workstations from an ergonomics point of view. By using the system, ergonomists, designers, engineers, and operators, can test design proposals of workstations in an immersive virtual environment while they see their ergonomics evaluation results displayed in real-time. The system allows its users to evaluate the ergonomics of the workplace in a pre-production phase. The workstation design can be modified, enabling workstation designers to better understand, test and evaluate how to create successful workstation designs, eventually to be used by the operators in production. This approach uses motion capture together with virtual reality and is aimed to complement and integrate with the use of digital human modelling (DHM) software at virtual stages of the production development process.

Ergonomics and efficient workplace design for hand-sewn footwear artisans in Kolhapur, India

BACKGROUND: The footwear manufacturing industry is one of the significant sectors of leather businesses in India. In the Indian footwear production industry, there is an enormous potential for employment, export, and development. Kolhapuri footwear is a popular handmade craft in India. It is a well-designed craft used by Indian people for many years. Artisans using traditional tools manufacture this footwear manually. Workers of this craft use traditional methods and work in cottage-based enterprises where organized laws and legislations are not applicable. Therefore, any occupational hazard-related documentation is not available. Due to the nature of the job, workers occupy various apparent non-optimal postures that may cause multiple work-related disorders such as musculoskeletal disorders (MSDs). OBJECTIVE: The main objective was to study and assess different footwear manufacturing workstations and working postures. The work further aimed to improve the design of current workstations and evaluate the proposed design using virtual ergonomic assessment techniques. METHODS: An anthropometric database for the Kolhapuri footwear making population was developed. This work measured 35 different body dimensions of the footwear manufacturing artisans. Rapid Upper Limb Assessment (RULA) was used for postural analysis of the artisans. RESULTS: It was observed that the entire footwear making activity was carried out in awkward postures. RULA scores suggested that ‘a change in posture’ to improve the efficiency of artisans was required for most of the workstations. This work proposed a novel workstation design to reduce the high risk of MSDs. The design was evaluated for thigh clearance, vision analysis and RULA analysis with the help of Digital Human Modelling (DHM). The virtual ergonomics assessment of this design revealed that the vision, thigh clearances, and RULA scores were satisfactory in the new design. CONCLUSION: The anthropometric database proposed in this study is likely to be useful in designing Kolhapuri footwear manufacturing tools. The proposed workstation and work layout are helpful to improve the accessibility of required tools and materials to footwear workers. It also helps to reduce occupational risks by easing uncomfortable work positions.