Composite structures such as hull of a ship and wings of aircraft are subjected to compressive loading. The behavior and strength of carbon fiber-reinforced polymer (CFRP) panels subjected to tensile loading has been studied rigorously by various researchers, whereas compressive behavior is not well addressed. In this study, behavior of CFRP panel with multiple interacting holes of various configurations (1H, 2HL, 2HT, and 2HD) under compressive loading is studied. A three-dimensional finite element-based progressive failure analysis (PFA) is used to model the damage progression in CFRP laminates. Damage detection is carried out using both Hashin’s failure and Ye’s-delamination criterions. Using these failure criterions, failure and post failure behavior of CFRP laminate with cutouts are predicted. The material is assumed to behave as linear elastic until final failure. Sudden degradation rule of material property is employed and subsequently PFA is carried out successively. Using digital image correlation (DIC) technique, whole field surface strain is obtained experimentally and is used for validating finite element analysis (FEA) model. Load–deflection behavior as well as path of damage progression is predicted by both PFA simulation and experiment. They are found to be in good agreement thereby confirming the accuracy of PFA implementation. Among all the configurations, one with two holes along the longitudinal direction (2HL) is recommended for design application as it exhibits low stress concentration factor and sustains higher initiation and final failure load.

Present work deals with evaluation of dynamic characteristics of a bus body structure. The bus under consideration is a sleeper non-air conditioned vehicle for a passenger capacity of thirty and it is designed adhering to automotive industry standards. Modal analysis of the proposed bus design is carried using Ansys Workbench. With the aid of modal analysis ten mode shapes of the bus are postulated, corresponding frequencies and deflections are estimated. Mesh generator is used to mesh the complex bus model. The deflection and frequency magnitudes of proposed bus model is found with the help of Finite Element Analysis (FEA) technique and they are in good agreement with experimental results available in literature. Engine being the prime source of excitation, it’s frequency is compared with the frequencies determined by FEA of the proposed bus body and it is observed that the frequencies of the bus body for ten different modes are far less than the minimum resonant engine frequency.

Self-weight and durability analysis of non-airconditioned sleeper bus has been carried in present work. Automotive industry standards (052 and 119) are used to freeze bus dimensions. Generative surface design is used in preparation to compute model. The bus superstructure behaviour is simulated for load on cant and waist rails for self-weight analysis. Bump analysis is carried out considering total failure of suspension system. Behaviour of bus during bump is simulated for two situations i.e. bump focre applied to front left wheel suspension location and all other suspension locations are fixed and force applied to front two wheel suspension locations and rear two wheel suspension locations are fixed. Behaviour of bus under torsional load for two cases viz first, force is applied to left of front suspension location in upward direction and other on to right suspension location in downward direction while the rear wheel suspension points are fixed and in second case, force is applied to left of front suspension in upward direction while the second one is applied to right in rear suspension location. Braking and double lane change load conditions are simulated with a braking efficiency of 80% and a lateral load of magnitude 0.4g is evaluated. Durability of the bus based on outcomes from braking, bump, torsional and double-lane change road-load situations is evaluated. The stress and deflection magnitudes are in good agreement with the results available in literature.

Crash analysis of non-air-conditioned sleeper bus has been carried in present work. Using relevant automotive industry standards (052 and 119) bus dimensions are considered for design. Surface modeling technique is used to prepare computer aided model. Further the bus design is freeze using finite element analysis for different crash conditions as front impact, side impact and rear impact. Crash analysis of the proposed bus design is carried using Ansys Workbench. Using the outcomes from finite element analysis as stresses, deflections, internal and kinetic energies during various crash conditions are estimated. Mesh generator is used to mesh the complex bus model. The stress and deflection magnitudes of proposed bus model are in good agreement with the experimental results available in literature. Design improvements are made using the finite element analysis outcomes, observing the deformation patterns additional pillar members of suitable length are added to increase the dynamic crush and further enhance occupant safety during collisions.